Run c55f0f7f

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0008 USD — 14803 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6123 bytes)
import geopandas as gpd

# Read the input file
parcels = gpd.read_file("parcels.geojson")

# Create a 25 metre buffer around every parcel
# Since the CRS is EPSG:3857 (meters), the buffer distance is in meters
buffers = parcels.buffer(25)

# Write the output file
buffers.to_file("simple_buffers.geojson")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0008 USD — 18518 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input parcels file
gdf = gpd.read_file('parcels.geojson')

# Apply a 25 metre buffer to the geometry column
# Since the CRS is EPSG:3857 (meters), the distance is interpreted correctly
gdf['geometry'] = gdf['geometry'].buffer(25.0)

# Write the buffered features to the output file
gdf.to_file('simple_buffers.geojson')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0011 USD — 19908 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6123 bytes)
import geopandas as gpd

# Read the input file parcels.geojson
# The task specifies the input is in EPSG:3857
parcels = gpd.read_file("parcels.geojson")

# Create a 25 metre buffer around every parcel polygon
# Since the CRS is projected (EPSG:3857), the distance is in meters
parcels['buffered_geometry'] = parcels.geometry.buffer(25.0)

# Create a new GeoDataFrame with the buffered geometries
# Preserve the original projected CRS
buffers = gpd.GeoDataFrame(geometry=parcels['buffered_geometry'], crs=parcels.crs)

# Write the output to simple_buffers.geojson
buffers.to_file("simple_buffers.geojson")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 1 — rejected — cost 0.0012 USD — 26064 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd
from shapely.geometry import shape

# Read the input parcels file
parcels = gpd.read_file('parcels.geojson')

# Create a 25 metre buffer around each parcel
# The CRS is projected (EPSG:3857), so the distance is interpreted as meters
parcels['buffered'] = parcels.geometry.buffer(25)

# Create a new GeoDataFrame with the buffered geometries
# Preserve original attributes and the projected CRS
buffers = parcels.copy()
buffers.geometry = parcels['buffered']

# Write the output file
buffers.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 17, in <module>
    buffers.to_file('simple_buffers.geojson', driver='GeoJSON')
  File "/usr/local/lib/python3.11/site-packages/geopandas/geodataframe.py", line 1632, in to_file
    _to_file(self, filename, driver, schema, index, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 718, in _to_file
    raise ValueError(
ValueError: GeoDataFrame contains multiple geometry columns but GeoDataFrame.to_file supports only a single geometry column. Use a GeoDataFrame.to_parquet or GeoDataFrame.to_feather, drop additional geometry columns or convert them to a supported format like a well-known text (WKT) using `GeoSeries.to_wkt()`.

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0007 USD — 15053 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input parcels file
gdf = gpd.read_file("parcels.geojson")

# Create a 25 metre buffer around each parcel
# Since the CRS is EPSG:3857 (meters), the distance is interpreted correctly
gdf['geometry'] = gdf['geometry'].buffer(25.0)

# Write the buffered geometries to the output file
gdf.to_file("simple_buffers.geojson")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0009 USD — 17107 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input file
parcels = gpd.read_file('parcels.geojson')

# Apply a 25 meter buffer to the geometry column
# The CRS is EPSG:3857 (meters), so the distance is directly applicable
parcels['geometry'] = parcels['geometry'].buffer(25.0)

# Write the output file
parcels.to_file('simple_buffers.geojson')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0017 USD — 23877 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6123 bytes)
import geopandas as gpd

# Load the input file parcels.geojson
parcels = gpd.read_file('parcels.geojson')

# Apply a 25-meter buffer to every geometry
# The buffer distance is in the units of the CRS (EPSG:3857 is meters)
buffers = parcels.buffer(distance=25, resolution=16)

# Write the resulting buffered GeoDataFrame to simple_buffers.geojson
buffers.to_file('simple_buffers.geojson')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Load the input file 'parcels.geojson' into a GeoDataFrame.",
    "Apply a 25-meter buffer to every geometry in the GeoDataFrame using the buffer method.",
    "Write the resulting buffered GeoDataFrame to 'simple_buffers.geojson' preserving the EPSG:3857 coordinate reference system."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm that 'simple_buffers.geojson' has been created.",
    "Verify that the output GeoDataFrame contains the same number of features as the input.",
    "Check that the output CRS is EPSG:3857."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0020 USD — 40205 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Load the input file
parcels = gpd.read_file('parcels.geojson')

# Apply a 25-meter buffer to each geometry
# The CRS is EPSG:3857 (meters), so 25 is the correct distance
parcels['geometry'] = parcels.buffer(25)

# Write the buffered geometries to the output file
parcels.to_file('simple_buffers.geojson')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Load the input file 'parcels.geojson' into a GeoDataFrame.",
    "Apply a 25-meter buffer to the geometry column using the buffer method.",
    "Write the resulting buffered GeoDataFrame to 'simple_buffers.geojson'."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm that 'simple_buffers.geojson' exists in the working directory.",
    "Verify that the output file contains the same number of features as the input.",
    "Verify that the CRS of the output file is EPSG:3857."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0023 USD — 42049 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Load the input parcels file
parcels = gpd.read_file('parcels.geojson')

# Apply a 25.0 meter buffer to the geometry column
parcels['geometry'] = parcels['geometry'].buffer(25.0)

# Write the buffered geometries to the output file
parcels.to_file('simple_buffers.geojson')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Load 'parcels.geojson' into a GeoDataFrame using geopandas.read_file.",
    "Apply a 25.0 meter buffer to the 'geometry' column using the shapely buffer method.",
    "Write the resulting GeoDataFrame to 'simple_buffers.geojson' using geopandas.to_file, preserving the EPSG:3857 coordinate reference system."
  ],
  "libraries": [
    "geopandas",
    "shapely",
    "pyproj"
  ],
  "validation": [
    "Confirm 'simple_buffers.geojson' exists in the working directory.",
    "Verify the output feature count matches the input feature count.",
    "Validate the output CRS is EPSG:3857.",
    "Check that all geometries are valid polygons."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0034 USD — 52672 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6123 bytes)
import geopandas as gpd

def main():
    # Load the input file
    parcels_gdf = gpd.read_file('parcels.geojson')
    
    # Ensure the CRS is EPSG:3857
    # We convert to ensure the buffer is calculated in meters
    parcels_gdf = parcels_gdf.to_crs(epsg=3857)
    
    # Apply a 25.0 meter buffer to all geometries
    # buffer returns a GeoDataFrame
    buffered_gdf = parcels_gdf.buffer(distance=25.0)
    
    # Write the output file
    buffered_gdf.to_file('simple_buffers.geojson')

if __name__ == '__main__':
    main()
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Load the input file 'parcels.geojson' into a GeoDataFrame.",
    "Ensure the GeoDataFrame's Coordinate Reference System (CRS) is EPSG:3857.",
    "Apply a 25.0 meter buffer to all geometries in the GeoDataFrame.",
    "Write the resulting buffered GeoDataFrame to 'simple_buffers.geojson'."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm 'simple_buffers.geojson' exists in the working directory.",
    "Verify the output file has the same number of features as the input.",
    "Verify the output CRS is EPSG:3857.",
    "Verify all geometries in the output are valid polygons."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0040 USD — 73399 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Load the input file
parcels = gpd.read_file("parcels.geojson")

# Ensure the GeoDataFrame uses EPSG:3857
if parcels.crs is None:
    parcels = parcels.to_crs("EPSG:3857")
else:
    assert parcels.crs.to_epsg() == 3857, "Input CRS is not EPSG:3857"

# Apply a 25-meter buffer to all geometries
parcels['geometry'] = parcels.buffer(25)

# Write the buffered GeoDataFrame to simple_buffers.geojson
parcels.to_file("simple_buffers.geojson")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Load parcels.geojson into a GeoDataFrame",
    "Ensure the GeoDataFrame uses EPSG:3857",
    "Apply a 25-meter buffer to all geometries",
    "Write the buffered GeoDataFrame to simple_buffers.geojson"
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that simple_buffers.geojson exists",
    "Verify the output file contains the same number of features as the input",
    "Confirm the output CRS is EPSG:3857",
    "Validate that all geometries in the output are valid polygons"
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-4.7-flash — exit 0 — accepted — cost 0.0037 USD — 76328 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Load the input file
gdf = gpd.read_file("parcels.geojson")

# Ensure the CRS is EPSG:3857
gdf = gdf.to_crs(epsg=3857)

# Apply a 25.0 meter buffer to all geometries
gdf['geometry'] = gdf.buffer(25.0)

# Write the result to the output file
gdf.to_file("simple_buffers.geojson")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Load 'parcels.geojson' into a GeoDataFrame, explicitly setting the Coordinate Reference System (CRS) to EPSG:3857.",
    "Apply a 25.0 meter buffer to the geometry column of the GeoDataFrame.",
    "Write the resulting buffered GeoDataFrame to 'simple_buffers.geojson', preserving the EPSG:3857 projection."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm 'simple_buffers.geojson' exists in the working directory.",
    "Confirm the output feature count matches the input feature count.",
    "Confirm the output CRS is EPSG:3857.",
    "Confirm all geometries are valid polygons."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0003 USD — 5647 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
gdf = gdf.to_crs(epsg=3857)
gdf["geometry"] = gdf.geometry.buffer(25)
gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0003 USD — 5724 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf = gdf.set_crs("EPSG:3857")
else:
    gdf = gdf.to_crs("EPSG:3857")

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)
buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0003 USD — 11416 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
else:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)
buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0003 USD — 11525 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
gdf = gdf.to_crs(epsg=3857)
buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)
buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0004 USD — 13435 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf = gdf.set_crs("EPSG:3857")
else:
    gdf = gdf.to_crs("EPSG:3857")

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0004 USD — 13643 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
else:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0010 USD — 15459 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    raise ValueError("Input CRS is missing; expected EPSG:3857.")
if gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

input_count = len(gdf)

buffered = gdf.copy()
buffered["geometry"] = buffered.buffer(25)

if len(buffered) != input_count:
    raise ValueError("Feature count mismatch after buffering.")

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")

out = gpd.read_file("simple_buffers.geojson")
if len(out) != input_count:
    raise ValueError("Output feature count does not match input feature count.")
if out.crs is None or out.crs.to_epsg() != 3857:
    raise ValueError("Output CRS is not EPSG:3857.")
if not out.geometry.is_valid.all():
    raise ValueError("Output contains invalid geometries.")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely.",
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file.",
    "Verify the GeoDataFrame CRS is EPSG:3857; if not, raise an error or reproject to EPSG:3857.",
    "Create a 25 metre buffer around every parcel polygon using GeoDataFrame.buffer(25).",
    "Assign the buffered geometries back to the GeoDataFrame geometry column.",
    "Write the result to simple_buffers.geojson using GeoDataFrame.to_file, preserving the projected CRS EPSG:3857.",
    "Confirm the output file contains one buffered feature per input parcel and no fabricated geometries."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm input feature count equals output feature count.",
    "Confirm output CRS is EPSG:3857.",
    "Confirm each output geometry is a valid Polygon/MultiPolygon created by buffering the corresponding input parcel.",
    "Confirm simple_buffers.geojson was written successfully."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0010 USD — 44636 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
elif gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered.geometry = gdf.buffer(25)
buffered = buffered.set_crs(epsg=3857, allow_override=True)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")

out = gpd.read_file("simple_buffers.geojson")
assert len(out) == len(gdf), "Feature count mismatch"
assert out.crs is not None and out.crs.to_epsg() == 3857, "Output CRS is not EPSG:3857"
assert out.geometry.notna().all(), "Some geometries are null"
assert out.geometry.is_valid.all(), "Some geometries are invalid"
assert not out.geometry.is_empty.any(), "Some geometries are empty"
assert list(out.columns) == list(gdf.columns), "Attributes changed"
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely.",
    "Read parcels.geojson using geopandas.read_file.",
    "Ensure the GeoDataFrame CRS is EPSG:3857; if missing or different, reproject to EPSG:3857.",
    "Create a 25 metre buffer around every parcel polygon using GeoDataFrame.buffer(25).",
    "Replace the active geometry column with the buffered geometries, preserving all original attributes and feature order.",
    "Set the GeoDataFrame CRS to EPSG:3857.",
    "Write the result to simple_buffers.geojson using to_file(driver='GeoJSON').",
    "Verify the output has the same number of features as the input and that all geometries are valid polygons."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm input and output feature counts match.",
    "Confirm output CRS is EPSG:3857.",
    "Confirm each output geometry is a valid shapely geometry and non-empty.",
    "Confirm no input attributes are lost."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 1 — accepted — cost 0.0018 USD — 15464 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered["geometry"] = gdf.geometry.buffer(25)
buffered = buffered.set_geometry("geometry")
buffered.crs = gdf.crs

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")

out = gpd.read_file("simple_buffers.geojson")
assert len(out) == len(gdf), "Feature count mismatch"
assert out.crs is not None and out.crs.to_epsg() == 3857, "Output CRS is not EPSG:3857"
assert out.geom_type.isin(["Polygon", "MultiPolygon"]).all(), "Invalid geometry types"
assert out.geometry.geom_all_valid(), "Invalid geometries present"
architecture=full-multi-agent
stage=planner
plan={"steps":["Import geopandas and shapely.","Read parcels.geojson into a GeoDataFrame using geopandas.read_file.","Verify the input CRS is EPSG:3857; if not, reproject to EPSG:3857 using to_crs.","Create a 25 metre buffer around every parcel polygon using GeoDataFrame.buffer(25).","Assign the buffered geometries to a new GeoDataFrame, preserving all original non-geometry attributes.","Set the buffered GeoDataFrame CRS to EPSG:3857 to preserve the projected CRS.","Write the result to simple_buffers.geojson using to_file with driver='GeoJSON'.","Ensure no input features are dropped and no fabricated geometries are created."],"libraries":["geopandas","shapely","pyproj"],"validation":["Confirm simple_buffers.geojson exists after writing.","Confirm the number of features in simple_buffers.geojson equals the number of features in parcels.geojson.","Confirm the output CRS is EPSG:3857.","Confirm every output geometry is a valid Polygon or MultiPolygon.","Confirm each output geometry is the 25 metre buffer of the corresponding input parcel geometry."]}
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 18, in <module>
    assert out.geometry.geom_all_valid(), "Invalid geometries present"
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/generic.py", line 6299, in __getattr__
    return object.__getattribute__(self, name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'GeoSeries' object has no attribute 'geom_all_valid'

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0012 USD — 15552 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
elif gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

assert len(gdf) > 0, "Input has no features"
assert gdf.geometry.notna().all(), "Input has null geometries"

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25, resolution=16)
buffered = gpd.GeoDataFrame(buffered, geometry="geometry", crs="EPSG:3857")

assert len(buffered) == len(gdf), "Feature count mismatch"
assert buffered.geometry.notna().all(), "Buffer produced null geometries"
assert buffered.geometry.is_valid.all(), "Buffer produced invalid geometries"
assert buffered.geometry.geom_type.isin(["Polygon", "MultiPolygon"]).all(), "Non-polygon buffer result"

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely in the Python sandbox.",
    "Read parcels.geojson using geopandas.read_file, ensuring the input is interpreted in EPSG:3857.",
    "If the loaded CRS is not EPSG:3857, reproject the GeoDataFrame to EPSG:3857 using to_crs(epsg=3857).",
    "Create a 25 metre buffer around every parcel polygon using the GeoDataFrame geometry buffer method with distance=25 and resolution=16.",
    "Replace the active geometry column with the buffered geometries while preserving all original attributes and row order.",
    "Set the GeoDataFrame CRS to EPSG:3857 to preserve the projected CRS.",
    "Write the result to simple_buffers.geojson using to_file with driver='GeoJSON'.",
    "Verify the output has the same number of features as the input and that all geometries are valid polygons/multipolygons."
  ],
  "libraries": [
    "geopandas",
    "shapely",
    "pyproj"
  ],
  "validation": [
    "Confirm parcels.geojson was read successfully and has a non-empty geometry column.",
    "Confirm the input GeoDataFrame CRS is EPSG:3857 or is reprojected to EPSG:3857 before buffering.",
    "Confirm the number of output features equals the number of input features.",
    "Confirm all output geometries are non-empty and valid after buffering.",
    "Confirm simple_buffers.geojson is written with CRS EPSG:3857 preserved.",
    "Confirm no input attributes were dropped and no fabricated geometries were added."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0018 USD — 19449 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf = gdf.set_crs("EPSG:3857")
else:
    gdf = gdf.to_crs("EPSG:3857")

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)
buffered = buffered.set_crs("EPSG:3857", allow_override=True)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")

out = gpd.read_file("simple_buffers.geojson")
assert len(out) == len(gdf), "Feature count mismatch"
assert out.crs == gdf.crs, "CRS mismatch"
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely.",
    "Read parcels.geojson using geopandas.read_file.",
    "Verify/assign the CRS is EPSG:3857; if missing, set it to EPSG:3857.",
    "Create a new geometry column by applying a 25 metre buffer to each parcel polygon using geometry.buffer(25).",
    "Construct the output GeoDataFrame preserving all original attributes and the buffered geometries.",
    "Set the output GeoDataFrame CRS to EPSG:3857.",
    "Write the result to simple_buffers.geojson using to_file(driver='GeoJSON').",
    "Confirm the output has one feature per input parcel and no dropped or fabricated geometries."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "simple_buffers.geojson exists in the working directory.",
    "Feature count in simple_buffers.geojson equals feature count in parcels.geojson.",
    "Output CRS is EPSG:3857.",
    "Each output geometry is a valid polygon or multipolygon resulting from a 25 metre buffer.",
    "No input attributes are lost."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/zai-org/glm-5.2 — exit 0 — accepted — cost 0.0017 USD — 21869 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf = gdf.set_crs(epsg=3857)
elif gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25)

assert len(buffered) == len(gdf), "Feature count mismatch"
assert buffered.crs is not None and buffered.crs.to_epsg() == 3857, "CRS is not EPSG:3857"

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely.",
    "Read parcels.geojson using geopandas.read_file.",
    "Ensure the GeoDataFrame is in EPSG:3857 using to_crs(epsg=3857) if needed.",
    "Create a 25 metre buffer around every geometry using GeoDataFrame.geometry.buffer(25).",
    "Assign the buffered geometries back to the GeoDataFrame geometry column.",
    "Verify the CRS is preserved as EPSG:3857.",
    "Write the result to simple_buffers.geojson using to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the output feature count equals the input feature count.",
    "Confirm the output CRS is EPSG:3857.",
    "Confirm each output geometry is a Polygon or MultiPolygon representing a 25 metre buffer.",
    "Confirm no input attributes are lost unless explicitly not required."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0004 USD — 5660 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
parcels = gpd.read_file('parcels.geojson')

# Create a 25 meter buffer around each parcel polygon
# The CRS is already projected (EPSG:3857), so buffer distance is in meters
parcels['geometry'] = parcels.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0005 USD — 7529 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file with its projected CRS (EPSG:3857)
parcels = gpd.read_file('parcels.geojson')

# Create a 25 meter buffer around each parcel polygon
parcels['geometry'] = parcels.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file, preserving the CRS
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0004 USD — 7859 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
parcels = gpd.read_file("parcels.geojson")

# Ensure the CRS is EPSG:3857 (Web Mercator)
parcels = parcels.to_crs(epsg=3857)

# Create a 25 meter buffer around each parcel polygon
parcels["geometry"] = parcels.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
parcels.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0004 USD — 7893 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
parcels = gpd.read_file('parcels.geojson')

# Create a 25 meter buffer around each parcel polygon
buffers = parcels.copy()
buffers['geometry'] = buffers.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
buffers.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0004 USD — 7171 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
parcels = gpd.read_file("parcels.geojson")

# Create a 25 meter buffer around each parcel polygon
# The CRS is already projected (EPSG:3857), so the buffer distance is in meters
parcels["geometry"] = parcels.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
parcels.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0004 USD — 7478 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
parcels = gpd.read_file("parcels.geojson")

# Create a 25 meter buffer around each parcel polygon
parcels["geometry"] = parcels.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
parcels.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0011 USD — 9299 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the CRS is EPSG:3857
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

# Apply a 25‑metre buffer to each geometry
gdf['geometry'] = gdf.geometry.buffer(25)

# Write the buffered geometries to the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas as gpd and shapely.geometry.",
    "Read the input file `parcels.geojson` using `gpd.read_file`, ensuring the CRS is EPSG:3857.",
    "Apply a 25‑metre buffer to each geometry: `gdf['geometry'] = gdf.geometry.buffer(25)`.",
    "Write the resulting GeoDataFrame to `simple_buffers.geojson` with `to_file`, preserving the CRS.",
    "Close any open file handles (if necessary)."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm that `simple_buffers.geojson` exists in the working directory.",
    "Verify that the CRS of the output file is EPSG:3857.",
    "Check that the number of features in the output equals the number of features in `parcels.geojson`.",
    "Ensure that each geometry in the output is a Polygon or MultiPolygon and is valid (no self‑intersections)."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0013 USD — 10392 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import os
import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

# Input and output filenames
input_file = "parcels.geojson"
output_file = "simple_buffers.geojson"

# Check that input file exists
if not os.path.isfile(input_file):
    raise FileNotFoundError(f"Input file '{input_file}' not found.")

# Read the GeoJSON file
gdf = gpd.read_file(input_file)

# Ensure CRS is EPSG:3857
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    raise ValueError(f"Input GeoDataFrame CRS is {gdf.crs}, expected EPSG:3857.")

# Buffer each geometry by 25 meters
buffered_geoms = gdf.geometry.buffer(25)

# Validate buffered geometries
for geom in buffered_geoms:
    if not isinstance(geom, (Polygon, MultiPolygon)):
        raise TypeError(f"Buffered geometry is not a Polygon or MultiPolygon: {geom}")

# Assign buffered geometries back to the GeoDataFrame
gdf["geometry"] = buffered_geoms

# Ensure the number of features remains the same
assert len(gdf) == len(gpd.read_file(input_file)), "Feature count mismatch after buffering."

# Write the output GeoJSON
gdf.to_file(output_file, driver="GeoJSON")

# Verify output file creation
if not os.path.isfile(output_file):
    raise RuntimeError(f"Failed to create output file '{output_file}'.")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file, ensuring the CRS is EPSG:3857.",
    "Apply a 25‑metre buffer to each geometry with the GeoDataFrame's .buffer(25) method (shapely is used internally).",
    "Assign the buffered geometries back to the GeoDataFrame, preserving all original attributes.",
    "Write the resulting GeoDataFrame to simple_buffers.geojson with gdf.to_file, keeping the CRS as EPSG:3857."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Verify that the input file exists and is readable.",
    "Confirm that the GeoDataFrame's CRS is EPSG:3857 before buffering.",
    "Check that each buffered geometry is a valid Polygon or MultiPolygon.",
    "Ensure that simple_buffers.geojson is created and contains the same number of features as the input."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0011 USD — 9651 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON file
gdf = gpd.read_file("parcels.geojson")

# Ensure the CRS is EPSG:3857
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

# Create a 25‑metre buffer around each geometry
buffered_geoms = gdf.geometry.buffer(25)

# Build a new GeoDataFrame with the buffered geometries
buffered_gdf = gpd.GeoDataFrame(gdf.drop(columns="geometry"), geometry=buffered_geoms, crs=gdf.crs)

# Write the buffered geometries to the output GeoJSON file
buffered_gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file, ensuring the CRS is EPSG:3857.",
    "Apply a 25‑metre buffer to each geometry with the GeoDataFrame's .buffer(25) method (shapely is used internally).",
    "Assign the buffered geometries back to a new GeoDataFrame, preserving the original CRS.",
    "Write the resulting GeoDataFrame to simple_buffers.geojson with geopandas.to_file, specifying driver='GeoJSON' and ensuring the CRS remains EPSG:3857."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm that the output GeoDataFrame has the same number of features as the input.",
    "Verify that each geometry is a Polygon or MultiPolygon after buffering.",
    "Check that the CRS of the output file is EPSG:3857."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0021 USD — 10219 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input GeoJSON
gdf = gpd.read_file("parcels.geojson")

# Ensure the CRS is EPSG:3857
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

# Buffer each geometry by 25 metres
gdf["geometry"] = gdf.geometry.buffer(25)

# Write the buffered geometries to a new GeoJSON file
gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file, ensuring the CRS is EPSG:3857.",
    "Apply a 25‑metre buffer to each geometry with the GeoDataFrame's .buffer(25) method (shapely is used internally).",
    "Assign the buffered geometries back to the GeoDataFrame, preserving all original attributes.",
    "Write the resulting GeoDataFrame to simple_buffers.geojson with geopandas.to_file, keeping the CRS as EPSG:3857."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm that the input GeoDataFrame has CRS EPSG:3857 before buffering.",
    "Verify that each buffered geometry is a valid Polygon or MultiPolygon.",
    "Check that the output file simple_buffers.geojson exists and contains the same number of features as the input."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0019 USD — 11394 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read input GeoJSON
gdf = gpd.read_file("parcels.geojson")

# Ensure CRS is EPSG:3857
if gdf.crs.to_epsg() != 3857:
    raise ValueError(f"Input CRS is {gdf.crs}, expected EPSG:3857")

# Buffer each geometry by 25 meters
buffered_geoms = gdf.geometry.buffer(25)

# Create new GeoDataFrame with buffered geometries
buffered_gdf = gpd.GeoDataFrame(gdf.drop(columns="geometry"), geometry=buffered_geoms, crs=gdf.crs)

# Write to output GeoJSON
buffered_gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file, ensuring the CRS is EPSG:3857.",
    "Apply a 25‑metre buffer to each geometry with the GeoDataFrame's .buffer(25) method.",
    "Create a new GeoDataFrame containing the buffered geometries, preserving the original CRS.",
    "Write the buffered GeoDataFrame to simple_buffers.geojson using GeoDataFrame.to_file with driver='GeoJSON'."
  ],
  "libraries": ["geopandas", "shapely"],
  "validation": [
    "Confirm that the input GeoDataFrame has CRS EPSG:3857 before buffering.",
    "Verify that each buffered geometry is a valid Polygon or MultiPolygon.",
    "Check that the output file simple_buffers.geojson exists and contains the same number of features as the input."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/openai/gpt-oss-20b — exit 0 — accepted — cost 0.0023 USD — 13755 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

# Read the input GeoJSON
gdf = gpd.read_file('parcels.geojson')

# Ensure the CRS is EPSG:3857
if gdf.crs is None or gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

# Apply a 25‑meter buffer to each geometry and clean any invalid geometries
gdf['geometry'] = gdf.geometry.buffer(25).buffer(0)

# Write the buffered geometries to the output file, preserving the CRS
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas as gpd and shapely.geometry.",
    "Read 'parcels.geojson' into a GeoDataFrame using gpd.read_file.",
    "Verify the GeoDataFrame's CRS is EPSG:3857.",
    "Apply a 25‑meter buffer to each geometry: gdf['geometry'] = gdf.geometry.buffer(25).",
    "Ensure the resulting geometries remain valid polygons.",
    "Write the buffered GeoDataFrame to 'simple_buffers.geojson' with gdf.to_file, preserving the CRS."
  ],
  "libraries": ["geopandas", "shapely"],
  "validation": [
    "Check that the output file contains the same number of features as the input.",
    "Confirm each geometry is a Polygon or MultiPolygon and is valid (no self‑intersections).",
    "Verify the CRS of the output file is EPSG:3857."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0006 USD — 12188 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input parcels file
    gdf = gpd.read_file('parcels.geojson')
    
    # Ensure the CRS is preserved and is projected (EPSG:3857 is in meters)
    # The task specifies the input is already in EPSG:3857
    
    # Create a 25 metre buffer around every parcel polygon
    # Since the CRS is EPSG:3857, the units are meters
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the output to simple_buffers.geojson
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0007 USD — 12559 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input parcels file
gdf = gpd.read_file('parcels.geojson')

# Create a 25 metre buffer around every parcel polygon
# Since the input is in EPSG:3857, the units are in meters
gdf['geometry'] = gdf.buffer(25)

# Write the output to simple_buffers.geojson preserving the CRS
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0007 USD — 13433 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input parcels file
gdf = gpd.read_file('parcels.geojson')

# Create a 25 metre buffer around every parcel polygon
# Since the input is in EPSG:3857, the units are in meters.
gdf['geometry'] = gdf.buffer(25)

# Write the result to simple_buffers.geojson, preserving the CRS
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0007 USD — 15173 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read the input parcels file
gdf = gpd.read_file('parcels.geojson')

# Apply a 25 metre buffer
# Since the input is in EPSG:3857, the units are already in meters.
gdf['geometry'] = gdf.buffer(25)

# Write the buffered geometries to the output file, preserving the CRS
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0005 USD — 11057 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input parcels file
    gdf = gpd.read_file('parcels.geojson')
    
    # Ensure the CRS is preserved (input is EPSG:3857)
    # Apply a 25 metre buffer to the geometry column
    # Since the input is already in a projected CRS (EPSG:3857), 
    # the buffer unit will be in meters.
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the output to simple_buffers.geojson
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0006 USD — 11538 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input parcels file
    gdf = gpd.read_file('parcels.geojson')
    
    # Create a 25 metre buffer around every parcel polygon
    # Since the input is in EPSG:3857, the units are already in meters
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the output to simple_buffers.geojson
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0013 USD — 15987 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input file
    gdf = gpd.read_file('parcels.geojson')
    
    # Apply a 25-meter buffer
    # Since the input is in EPSG:3857, units are in meters
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the resulting GeoDataFrame to the output file
    # The CRS is preserved from the original GeoDataFrame
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' into a GeoDataFrame using geopandas.",
    "Apply a 25-meter buffer operation to the geometry column of the GeoDataFrame using the .buffer() method.",
    "Write the resulting GeoDataFrame to 'simple_buffers.geojson' while ensuring the EPSG:3857 CRS is preserved."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Verify that the number of features in the output matches the number of features in the input.",
    "Confirm that the CRS of the output file is EPSG:3857.",
    "Ensure the buffer distance is approximately 25 units (meters) in the projected coordinate system."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0013 USD — 16825 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input file
    gdf = gpd.read_file('parcels.geojson')
    
    # Ensure we are working with the geometry column and apply a 25m buffer
    # Since the input is in EPSG:3857 (meters), the buffer distance is in meters
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the resulting GeoDataFrame to the output file
    # The CRS is preserved from the original GeoDataFrame
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' using geopandas.",
    "Apply a 25-meter buffer operation to the geometry column of the GeoDataFrame.",
    "Save the resulting GeoDataFrame to 'simple_buffers.geojson' while preserving the EPSG:3857 CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Verify that the number of features in the output matches the number of features in the input.",
    "Confirm that the output CRS is EPSG:3857.",
    "Ensure the output file is a valid GeoJSON."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0014 USD — 18370 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input file
    input_filename = 'parcels.geojson'
    output_filename = 'simple_buffers.geojson'
    
    gdf = gpd.read_file(input_filename)
    
    # Ensure the CRS is EPSG:3857 as specified to ensure buffer is in meters
    # If it's not, we should ideally reproject, but the prompt says it is in 3857.
    if gdf.crs is None or gdf.crs.to_epsg() != 3857:
        gdf = gdf.to_crs(epsg=3857)
    
    # Apply a 25-meter buffer
    # gdf.buffer() returns a GeoSeries of buffered geometries
    buffered_gdf = gdf.copy()
    buffered_gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the output file
    buffered_gdf.to_file(output_filename, driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' using geopandas.",
    "Verify that the input CRS is EPSG:3857 to ensure the buffer distance (25m) is applied in meters.",
    "Apply a 25-meter buffer to the geometry column of the GeoDataFrame using the .buffer() method.",
    "Save the resulting GeoDataFrame to 'simple_buffers.geojson' while preserving the original CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the output file 'simple_buffers.geojson' contains the same number of features as the input.",
    "Verify the output CRS is EPSG:3857.",
    "Check that the geometries in the output are indeed buffered versions of the input."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0028 USD — 27709 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input file
    gdf = gpd.read_file('parcels.geojson')
    
    # Ensure the CRS is EPSG:3857 to ensure the buffer distance of 25 is interpreted as 25 meters
    if gdf.crs is None or gdf.crs.to_epsg() != 3857:
        gdf = gdf.to_crs(epsg=3857)
    
    # Apply a 25-meter buffer
    # The buffer method in geopandas/shapely uses the units of the CRS
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the resulting GeoDataFrame to 'simple_buffers.geojson'
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' into a GeoDataFrame using geopandas.",
    "Verify that the CRS is EPSG:3857 to ensure the buffer distance of 25 is interpreted as 25 meters.",
    "Apply a 25-meter buffer to the geometry column of the GeoDataFrame using the .buffer() method.",
    "Write the resulting GeoDataFrame to 'simple_buffers.geojson' while preserving the CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the output file 'simple_buffers.geojson' exists.",
    "Verify that the number of features in the output matches the number of features in the input.",
    "Check that the CRS of the output file is EPSG:3857.",
    "Ensure the geometries in the output are buffered versions of the input."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0032 USD — 34553 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    input_filename = 'parcels.geojson'
    output_filename = 'simple_buffers.geojson'
    
    # Read the input file
    gdf = gpd.read_file(input_filename)
    
    # Ensure the CRS is EPSG:3857 to ensure the buffer distance is in meters
    if gdf.crs is None or gdf.crs.to_epsg() != 3857:
        gdf = gdf.to_crs(epsg=3857)
    
    # Apply a 25-meter buffer to the geometry column
    # Using gdf.geometry.buffer ensures we are operating on the geometry series
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the resulting GeoDataFrame to the output file, preserving the CRS
    gdf.to_file(output_filename, driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' into a GeoDataFrame using geopandas.",
    "Verify that the CRS is EPSG:3857 to ensure the buffer distance is in meters.",
    "Apply a 25-meter buffer to the geometry column of the GeoDataFrame using the .buffer() method.",
    "Write the resulting GeoDataFrame to 'simple_buffers.geojson', ensuring the CRS is preserved."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the number of features in 'simple_buffers.geojson' matches 'parcels.geojson'.",
    "Verify that the CRS of the output file is EPSG:3857.",
    "Ensure no features were dropped during the buffering process."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/google/gemma-4-26b-a4b-it — exit 0 — accepted — cost 0.0033 USD — 37715 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

def main():
    # Read the input file 'parcels.geojson'
    gdf = gpd.read_file('parcels.geojson')
    
    # The task specifies the input is in EPSG:3857.
    # In EPSG:3857, units are meters, so a buffer of 25 is 25 meters.
    # Apply the 25-meter buffer to the geometry column.
    # We use gdf.geometry.buffer to ensure we are calling the method on the GeoSeries.
    gdf['geometry'] = gdf.geometry.buffer(25)
    
    # Write the resulting GeoDataFrame to 'simple_buffers.geojson'
    # preserving the original CRS.
    gdf.to_file('simple_buffers.geojson', driver='GeoJSON')

if __name__ == "__main__":
    main()
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read the input file 'parcels.geojson' into a GeoDataFrame using geopandas.",
    "Verify that the CRS is EPSG:3857 to ensure the buffer distance of 25 is interpreted as meters.",
    "Apply a 25-meter buffer to the geometry column of the GeoDataFrame using the .buffer() method.",
    "Write the resulting GeoDataFrame to 'simple_buffers.geojson', preserving the original CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Verify that the number of features in 'simple_buffers.geojson' matches the number of features in 'parcels.geojson'.",
    "Confirm that the CRS of the output file is EPSG:3857.",
    "Check that the geometries in the output file are indeed buffered versions of the input geometries."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0008 USD — 17113 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
parcels['geometry'] = parcels.geometry.buffer(25)
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0019 USD — 31081 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0019 USD — 32352 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0019 USD — 32301 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0014 USD — 29406 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")
gdf = gdf.set_crs(epsg=3857, allow_override=True)
gdf["geometry"] = gdf.geometry.buffer(25)
gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0034 USD — 55464 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=plan-then-act
stage=planner
plan={"steps":["Load parcels.geojson into a GeoDataFrame using geopandas.read_file.","Verify the GeoDataFrame CRS is EPSG:3857.","Apply a 25-metre buffer to each parcel geometry using .buffer(25), producing exactly one buffered geometry per input feature.","Construct a new GeoDataFrame with the buffered geometries while preserving the original attributes and row order.","Confirm the output GeoDataFrame retains the projected CRS EPSG:3857.","Write the resulting GeoDataFrame to simple_buffers.geojson using .to_file with the GeoJSON driver."],"libraries":["geopandas","shapely"],"validation":["simple_buffers.geojson exists and is non-empty.","Output feature count equals input parcels.geojson feature count.","Output CRS is EPSG:3857.","All buffered geometries are valid, non-null, and of type Polygon or MultiPolygon.","No features were dropped, duplicated, or fabricated during processing."]}
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0028 USD — 60421 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import shapely

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)

buffered = gdf.copy()
buffered.geometry = gdf.geometry.buffer(25)

assert len(buffered) == len(gdf), "Feature count mismatch"
assert buffered.crs.to_epsg() == 3857, "CRS not preserved"
assert not buffered.geometry.isna().any(), "Null geometries found"
assert not buffered.geometry.is_empty.any(), "Empty geometries found"
assert buffered.geometry.geom_type.isin(["Polygon", "MultiPolygon"]).all(), "Invalid geometry types"

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file().",
    "Verify the GeoDataFrame CRS is EPSG:3857.",
    "Apply a 25-metre buffer to each geometry using gdf.geometry.buffer(25).",
    "Construct a new GeoDataFrame with the buffered geometries, retaining all original columns and preserving the EPSG:3857 CRS.",
    "Write the resulting GeoDataFrame to simple_buffers.geojson using to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Output feature count equals input feature count (no features dropped or fabricated).",
    "Output CRS is EPSG:3857.",
    "No null or empty geometries exist in the output.",
    "All output geometries are Polygon or MultiPolygon types."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0019 USD — 47168 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0017 USD — 79294 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import shapely

gdf = gpd.read_file("parcels.geojson")
gdf["geometry"] = gdf.geometry.buffer(25)
gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0044 USD — 74242 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import shapely

gdf = gpd.read_file("parcels.geojson")

assert gdf.crs is not None, "Missing input CRS"
assert gdf.crs.to_string() == "EPSG:3857", f"Input CRS is {gdf.crs}, expected EPSG:3857"

input_count = len(gdf)

gdf["geometry"] = gdf.geometry.buffer(25)

assert len(gdf) == input_count, "Feature count mismatch after buffering"
assert gdf.geometry.isna().sum() == 0, "Buffered geometries contain None"
assert gdf.geometry.is_empty.sum() == 0, "Buffered geometries contain empty polygons"
assert all(shapely.is_valid(g) for g in gdf.geometry), "Buffered geometries contain invalid polygons"

gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan={"steps":["Load parcels.geojson into a GeoDataFrame using geopandas.read_file.","Verify the GeoDataFrame CRS is EPSG:3857.","Apply a 25-metre buffer to each geometry with GeoSeries.buffer(25).","Assign the buffered geometries back to the GeoDataFrame, preserving all rows and attributes.","Write the result to simple_buffers.geojson using to_file with the GeoJSON driver, retaining the projected CRS."],"libraries":["geopandas","shapely"],"validation":["Confirm simple_buffers.geojson exists and has size greater than zero.","Assert the output feature count equals the input feature count.","Assert the output CRS is EPSG:3857.","Assert no output geometries are None or empty.","Optionally check that all buffered geometries are valid using shapely.is_valid."]}
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — accepted — cost 0.0029 USD — 81949 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import os

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    gdf.set_crs("EPSG:3857", inplace=True)
else:
    gdf = gdf.to_crs("EPSG:3857")

buffered = gdf.copy()
buffered.geometry = gdf.geometry.buffer(25)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")

assert os.path.exists("simple_buffers.geojson")
out = gpd.read_file("simple_buffers.geojson")
assert len
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file().",
    "Verify the GeoDataFrame CRS is EPSG:3857.",
    "Apply a 25-metre buffer to each parcel geometry using GeoDataFrame.geometry.buffer(25) to produce new shapely geometries.",
    "Construct a new GeoDataFrame using the buffered geometries and the original attribute table, preserving the EPSG:3857 CRS.",
    "Write the resulting GeoDataFrame to simple_buffers.geojson using to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Assert simple_buffers.geojson exists on disk.",
    "Assert the output feature count equals the input feature count.",
    "Assert the output CRS string matches EPSG:3857.",
    "Assert no empty or null geometries exist in the output.",
    "Assert all output geometries are valid polygons or multi-polygons."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 1 — rejected — cost 0.0054 USD — 82424 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    gdf = gdf.set_crs(epsg=3857)

buffered = gdf.copy()
buffered.geometry = gdf.geometry.buffer(25)

assert buffered.crs.to_string() == "EPSG:3857"
assert len(buffered) == len(gdf)
assert buffered.geometry.isna().sum() == 0
assert buffered.geometry.is_empty
architecture=full-multi-agent
stage=planner
plan={"steps":["Import geopandas and shapely.geometry.","Read parcels.geojson into a GeoDataFrame with geopandas.read_file.","Verify the GeoDataFrame CRS is EPSG:3857; set it explicitly if the metadata is missing.","Apply a 25-metre buffer to every geometry using gdf.geometry.buffer(25) to produce one buffered polygon per input parcel.","Construct a new GeoDataFrame (or assign back) containing the buffered geometries, preserving all original attributes and the EPSG:3857 CRS.","Write the resulting GeoDataFrame to simple_buffers.geojson using to_file with driver='GeoJSON'."],"libraries":["geopandas","shapely"],"validation":["Assert simple_buffers.geojson exists on disk.","Assert the output feature count equals the input feature count.","Assert the output GeoDataFrame CRS is EPSG:3857.","Assert no null, empty, or missing geometries are present in the output.","Assert every output geometry is of type Polygon or MultiPolygon.","Assert each buffered geometry has an area greater than or equal to its original parcel area."]}
stage=builder
stage=auditor
auditor_output_present=false
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 15, in <module>
    assert buffered.geometry.is_empty
  File "/usr/local/lib/python3.11/site-packages/pandas/core/generic.py", line 1577, in __nonzero__
    raise ValueError(
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

# attempt undefined — model: @cf/moonshotai/kimi-k2.6 — exit 0 — rejected — cost 0.0050 USD — 91420 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=full-multi-agent
stage=planner
plan={"steps":["Read parcels.geojson into a GeoDataFrame using geopandas.read_file().","Record the input CRS and confirm it is EPSG:3857.","Apply a 25-metre buffer to each geometry via gdf.geometry.buffer(25).","Replace the original geometry column with the buffered geometries, keeping all rows and attributes intact.","Explicitly set the output GeoDataFrame CRS to the original EPSG:3857.","Write the result to simple_buffers.geojson using to_file(driver='GeoJSON')."],"libraries":["geopandas","shapely"],"validation":["Verify simple_buffers.geojson exists after writing.","Verify the output feature count matches the input feature count.","Verify the output CRS is EPSG:3857.","Verify no null or empty geometries are present in the output.","Verify all output geometries are valid Polygons or MultiPolygons."]}
stage=builder
stage=auditor
auditor_output_present=false
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0007 USD — 14630 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import shapely

gdf = gpd.read_file("parcels.geojson")
if gdf.crs is None:
    gdf = gdf.set_crs(epsg=3857)
else:
    gdf = gdf.to_crs(epsg=3857)

buffered = gdf.copy()
buffered["geometry"] = buffered.geometry.buffer(25, resolution=16)

buffered.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0011 USD — 25043 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')

if gdf.crs is None:
    gdf = gdf.set_crs('EPSG:3857')
else:
    gdf = gdf.to_crs('EPSG:3857')

gdf['geometry'] = gdf.geometry.buffer(25)

gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0015 USD — 27227 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file("parcels.geojson")

if parcels.crs is None:
    parcels = parcels.set_crs(epsg=3857)
else:
    parcels = parcels.to_crs(epsg=3857)

buffers = parcels.copy()
buffers.geometry = buffers.geometry.buffer(25)

buffers.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — rejected — cost 0.0035 USD — 61432 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0010 USD — 12329 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")

assert gdf.crs is not None and gdf.crs.to_epsg() == 3857, "Input CRS must be EPSG:3857"

gdf["geometry"] = gdf.geometry.buffer(25)

gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Load parcels.geojson using geopandas.read_file() and verify the CRS is EPSG:3857.",
    "Apply a 25-metre buffer to every parcel geometry using GeoSeries.buffer(25) or shapely buffer, preserving all attribute columns and the original index.",
    "Assign the buffered geometries back to the GeoDataFrame and ensure the CRS remains EPSG:3857.",
    "Write the result to simple_buffers.geojson using GeoDataFrame.to_file(driver='GeoJSON') with the projected CRS preserved."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Input and output feature counts are identical (no dropped or fabricated features).",
    "Output CRS equals EPSG:3857.",
    "All output geometries are valid Polygon or MultiPolygon geometries.",
    "Each buffered geometry fully contains or equals its corresponding input parcel geometry (25 m buffer applied)."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0011 USD — 17735 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    gdf.set_crs(epsg=3857, inplace=True)
else:
    gdf = gdf.to_crs(epsg=3857)

gdf["geometry"] = gdf.geometry.buffer(25)

gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson using geopandas.read_file().",
    "Verify the GeoDataFrame CRS is EPSG:3857; assert or set it if necessary.",
    "Apply a 25-metre buffer to every parcel geometry using GeoDataFrame.buffer(25) or shapely.buffer, producing one buffered polygon per input parcel.",
    "Assign the buffered geometries back to the GeoDataFrame, preserving all original attributes and the projected CRS.",
    "Write the result to simple_buffers.geojson using to_file(driver='GeoJSON') with CRS preserved."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Input and output feature counts are equal (no dropped or fabricated features).",
    "Output CRS is EPSG:3857.",
    "All output geometries are valid Polygon/MultiPolygon geometries.",
    "No null or empty geometries exist in the output.",
    "Buffer operation used a distance of 25 metres in the projected CRS units."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0009 USD — 21428 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    gdf = gdf.set_crs(epsg=3857)

gdf["geometry"] = gdf.geometry.buffer(25)

gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — rejected — cost 0.0035 USD — 56742 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced

architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0016 USD — 86286 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (5692 bytes)
import geopandas as gpd

gdf = gpd.read_file("parcels.geojson")

if gdf.crs is None:
    gdf = gdf.set_crs("EPSG:3857")
else:
    gdf = gdf.to_crs("EPSG:3857")

gdf["geometry"] = gdf.geometry.buffer(25)

with open("simple_buffers.geojson", "w") as f:
    f.write(gdf.to_json())
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0012 USD — 16204 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

# Read input parcels
parcels = gpd.read_file("parcels.geojson")

# Verify projected CRS for metre-based buffering
if parcels.crs is None:
    parcels = parcels.set_crs(epsg=3857)
elif parcels.crs.to_epsg() != 3857:
    parcels = parcels.to_crs(epsg=3857)

# Apply 25-metre buffer to every parcel geometry
buffered_geoms = parcels.geometry.buffer(25)

# Construct output GeoDataFrame preserving original attributes and CRS
buffers = gpd.GeoDataFrame(
    parcels.drop(columns="geometry").copy(),
    geometry=buffered_geoms,
    crs=parcels.crs
)

# Ensure all geometries are valid
buffers["geometry"] = buffers.geometry.make_valid()

# Write output GeoJSON preserving projected CRS
buffers.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file.",
    "Verify the GeoDataFrame CRS is EPSG:3857; ensure it remains projected for metre-based buffering.",
    "Apply a 25-metre buffer to every parcel geometry using GeoDataFrame.geometry.buffer(25).",
    "Construct a new GeoDataFrame containing the buffered geometries and the original parcel attributes, preserving the EPSG:3857 CRS.",
    "Write the result to simple_buffers.geojson using GeoDataFrame.to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the output feature count equals the input feature count (no dropped or fabricated features).",
    "Confirm the output CRS is EPSG:3857.",
    "Confirm all output geometries are valid polygons/multipolygons and non-null.",
    "Confirm each buffered geometry fully contains or equals its corresponding input parcel geometry."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0022 USD — 25566 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
import shapely

# Read the input parcels
gdf = gpd.read_file("parcels.geojson")

# Ensure the GeoDataFrame has the projected CRS EPSG:3857
if gdf.crs is None:
    gdf = gdf.set_crs(epsg=3857)
elif gdf.crs.to_epsg() != 3857:
    gdf = gdf.to_crs(epsg=3857)

# Apply a 25-metre buffer to each parcel geometry, preserving attributes
gdf["geometry"] = gdf.geometry.buffer(25)

# Write the buffered parcels to the output GeoJSON, preserving the CRS
gdf.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Import geopandas and shapely.",
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file().",
    "Verify the GeoDataFrame has a projected CRS (EPSG:3857).",
    "Apply a 25-metre buffer to each parcel geometry using GeoDataFrame.geometry.buffer(25).",
    "Assign the buffered geometries back to the GeoDataFrame, preserving all attributes and the original CRS.",
    "Write the result to simple_buffers.geojson using GeoDataFrame.to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm simple_buffers.geojson exists in the working directory.",
    "Confirm the output CRS is EPSG:3857.",
    "Confirm the output feature count equals the input parcels.geojson feature count.",
    "Confirm each output geometry is a valid polygonal buffer and no null geometries were introduced."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 0 — accepted — cost 0.0034 USD — 42369 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon, MultiPolygon

# Read input
parcels = gpd.read_file("parcels.geojson")

# Verify projected CRS
if parcels.crs is None:
    raise ValueError("Input parcels.geojson has no CRS.")
if parcels.crs.to_epsg() != 3857:
    parcels = parcels.to_crs(epsg=3857)

# Apply 25-metre buffer
buffered_geoms = parcels.geometry.buffer(25)

# Build output GeoDataFrame preserving attributes and CRS
buffers = gpd.GeoDataFrame(
    parcels.drop(columns=parcels.geometry.name),
    geometry=buffered_geoms,
    crs=parcels.crs
)

# Validation
assert len(buffers) == len(parcels), "Feature count mismatch."
assert buffers.crs.to_epsg() == 3857, "Output CRS is not EPSG:3857."
assert buffers.geometry.notna().all(), "Output contains null geometries."
assert (~buffers.geometry.is_empty).all(), "Output contains empty geometries."
valid_types = buffers.geometry.apply(lambda g: isinstance(g, (Polygon, MultiPolygon)))
assert valid_types.all(), "Output contains non-polygon geometries."

# Write result
buffers.to_file("simple_buffers.geojson", driver="GeoJSON")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson into a GeoDataFrame using geopandas.read_file.",
    "Verify the input CRS is EPSG:3857; preserve it for the output.",
    "Apply a 25-metre buffer to every parcel geometry using GeoDataFrame.geometry.buffer(25).",
    "Construct a new GeoDataFrame containing the buffered geometries and the original parcel attributes.",
    "Assign the same EPSG:3857 CRS to the new GeoDataFrame.",
    "Write the result to simple_buffers.geojson using GeoDataFrame.to_file(driver='GeoJSON')."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm the output feature count equals the input feature count.",
    "Confirm the output CRS is EPSG:3857.",
    "Confirm every output geometry is a valid Polygon or MultiPolygon.",
    "Confirm no null or empty geometries exist in the output.",
    "Confirm the buffer was applied in projected metres consistent with EPSG:3857."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/moonshotai/kimi-k2.7-code — exit 1 — rejected — cost 0.0035 USD — 45434 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd

# Read input parcels
gdf = gpd.read_file("parcels.geojson")

# Verify projected CRS
assert gdf.crs is not None, "Input CRS is missing"
assert gdf.crs.to_epsg() == 3857, f"Expected EPSG:3857, got {gdf.crs.to_epsg()}"

# Record input feature count and original geometries
input_count = len(gdf)
original_geom = gdf.geometry.copy()

# Apply a 25-metre buffer to each parcel geometry
gdf["geometry"] = gdf.geometry.buffer(25)

# Validate no features were dropped and geometries are valid
assert len(gdf) == input_count, "Feature count changed after buffering"
assert gdf.geometry.is_valid.all(), "Some buffered geometries are invalid"
assert gdf.geometry.notna().all(), "Some buffered geometries are null"

# Validate buffered geometries cover original parcels
assert gdf.geometry.covers(original_geom).all(), "Buffered geometries do not cover original parcels"

# Ensure CRS is preserved
gdf = gdf.set_crs(epsg=3857)

# Write output, preserving the projected CRS
gdf.to_file("simple_buffers.geojson", driver="GeoJSON", crs="EPSG:3857")
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read parcels.geojson using geopandas.read_file and verify the CRS is EPSG:3857.",
    "Apply a 25-metre buffer to each parcel geometry using GeoDataFrame.buffer(25).",
    "Assign the buffered geometries back to the GeoDataFrame, preserving all original attributes and the original CRS.",
    "Write the result to simple_buffers.geojson using to_file with driver='GeoJSON' and CRS=EPSG:3857."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Confirm input CRS is EPSG:3857 and output CRS matches.",
    "Confirm output feature count equals input feature count.",
    "Confirm every output geometry is a valid Polygon/MultiPolygon and encloses the original parcel by at least 25 metres.",
    "Confirm no null or fabricated geometries were introduced."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 29, in <module>
    gdf.to_file("simple_buffers.geojson", driver="GeoJSON", crs="EPSG:3857")
  File "/usr/local/lib/python3.11/site-packages/geopandas/geodataframe.py", line 1632, in to_file
    _to_file(self, filename, driver, schema, index, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 731, in _to_file
    _to_file_pyogrio(df, filename, driver, schema, crs, mode, metadata, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 787, in _to_file_pyogrio
    raise ValueError("Passing 'crs' is not supported with the 'pyogrio' engine.")
ValueError: Passing 'crs' is not supported with the 'pyogrio' engine.

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 6191 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Load the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a buffer of 25 meters around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 6952 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Load the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a 25-meter buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 7359 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Load the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a 25-meter buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 8442 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a buffer of 25 meters around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 7617 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Load the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a buffer of 25 meters around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0003 USD — 9102 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Create a 25-meter buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the output GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0009 USD — 11835 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the GeoDataFrame is in the correct CRS (EPSG:3857)
gdf = gdf.set_crs(epsg=3857, allow_override=True)

# Create a 25-metre buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the resulting GeoDataFrame to a new GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input GeoJSON file 'parcels.geojson' into a GeoDataFrame using geopandas.",
    "Ensure the GeoDataFrame is in the correct CRS (EPSG:3857).",
    "Create a 25-metre buffer around each parcel polygon using the buffer method from shapely.",
    "Assign the buffered geometries back to the GeoDataFrame.",
    "Write the resulting GeoDataFrame to a new GeoJSON file 'simple_buffers.geojson' preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that the input file 'parcels.geojson' exists and is readable.",
    "Verify that the output file 'simple_buffers.geojson' is created and contains the expected number of features.",
    "Ensure that each feature in the output file has a buffered geometry."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0009 USD — 14116 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the data is in the correct projected CRS (EPSG:3857)
gdf = gdf.set_crs(epsg=3857, allow_override=True, inplace=False)

# Create a 25-metre buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the buffered geometries to a new GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input GeoJSON file 'parcels.geojson' using Geopandas.",
    "Ensure the data is in the correct projected CRS (EPSG:3857).",
    "Create a 25-metre buffer around each parcel polygon using Shapely.",
    "Write the buffered geometries to a new GeoJSON file 'simple_buffers.geojson' preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that the input file 'parcels.geojson' exists and is readable.",
    "Verify that the output file 'simple_buffers.geojson' contains the same number of features as the input file.",
    "Ensure that each feature in the output file is a buffered version of the corresponding feature in the input file."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0008 USD — 10021 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the data is in the correct projected CRS (EPSG:3857)
gdf = gdf.to_crs(epsg=3857)

# Create a 25-metre buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the buffered geometries to a new GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan=```json
{
  "steps": [
    "Read the input GeoJSON file 'parcels.geojson' using GeoPandas.",
    "Ensure the data is in the correct projected CRS (EPSG:3857).",
    "Create a 25-metre buffer around each parcel polygon using Shapely.",
    "Write the buffered geometries to a new GeoJSON file 'simple_buffers.geojson' preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that the input file 'parcels.geojson' exists and is readable.",
    "Verify that the output file 'simple_buffers.geojson' is created and contains the expected number of features.",
    "Ensure that each feature in the output file has a buffered geometry."
  ]
}
```
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0016 USD — 14635 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Load the input GeoJSON file
parcels = gpd.read_file('parcels.geojson')

# Ensure the data is in the correct projected CRS (EPSG:3857)
parcels = parcels.to_crs(epsg=3857)

# Create a 25-metre buffer around each parcel polygon
parcels['geometry'] = parcels['geometry'].buffer(25)

# Write the resulting GeoDataFrame to a new GeoJSON file
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Load the input GeoJSON file 'parcels.geojson' using geopandas.",
    "Ensure the data is in the correct projected CRS (EPSG:3857).",
    "Create a 25-metre buffer around each parcel polygon using shapely.",
    "Store the buffered geometries in a new GeoDataFrame.",
    "Write the resulting GeoDataFrame to a new GeoJSON file 'simple_buffers.geojson' preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that the input file 'parcels.geojson' is successfully loaded.",
    "Verify that the CRS of the input data is EPSG:3857.",
    "Confirm that the buffer operation is applied correctly to each parcel polygon.",
    "Ensure that the output file 'simple_buffers.geojson' is written successfully and contains the buffered geometries."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0015 USD — 15522 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the data is in the correct projected CRS (EPSG:3857)
gdf = gdf.set_crs(epsg=3857, allow_override=True)

# Create a 25-metre buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the buffered geometries to a new GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read the input GeoJSON file 'parcels.geojson' using GeoPandas.",
    "Ensure the data is in the correct projected CRS (EPSG:3857).",
    "Create a 25-metre buffer around each parcel polygon using Shapely.",
    "Write the buffered geometries to a new GeoJSON file 'simple_buffers.geojson' preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Check that the input file 'parcels.geojson' exists and is readable.",
    "Verify that the output file 'simple_buffers.geojson' is created and contains the same number of features as the input file.",
    "Ensure that each feature in the output file has a buffered geometry."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/mistralai/mistral-small-3.1-24b-instruct — exit 0 — accepted — cost 0.0015 USD — 18925 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd
from shapely.geometry import Polygon

# Read the input GeoJSON file
gdf = gpd.read_file('parcels.geojson')

# Ensure the GeoDataFrame is in EPSG:3857
gdf = gdf.set_crs(epsg=3857, allow_override=True)

# Create a 25-meter buffer around each parcel polygon
gdf['geometry'] = gdf['geometry'].buffer(25)

# Write the buffered geometries to a new GeoJSON file
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=full-multi-agent
stage=planner
plan=```json
{
  "steps": [
    "Read the input GeoJSON file 'parcels.geojson' using Geopandas, ensuring it is in EPSG:3857.",
    "Create a 25-meter buffer around each parcel polygon using Shapely.",
    "Write the buffered geometries to a new GeoJSON file 'simple_buffers.geojson', preserving the projected CRS."
  ],
  "libraries": [
    "geopandas",
    "shapely"
  ],
  "validation": [
    "Verify that the input file 'parcels.geojson' is read correctly and contains valid geometries.",
    "Check that the buffered geometries are created correctly and have the expected properties.",
    "Ensure that the output file 'simple_buffers.geojson' is written correctly and contains the buffered geometries in the same CRS as the input."
  ]
}
```
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0008 USD — 11053 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf['geometry'] = gdf.geometry.buffer(25)
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0008 USD — 13714 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf['geometry'] = gdf.buffer(25)
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0009 USD — 14060 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
buffers = parcels.copy()
buffers['geometry'] = buffers.geometry.buffer(25)
buffers.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-shot
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0008 USD — 17742 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
buffered = gdf.copy()
buffered['geometry'] = gdf.geometry.buffer(25)
buffered.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0011 USD — 15110 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf['geometry'] = gdf.geometry.buffer(25)
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0008 USD — 21944 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf['geometry'] = gdf.geometry.buffer(25)
gdf.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=single-retry
stage=single-code-generation
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0017 USD — 26987 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
parcels['geometry'] = parcels['geometry'].buffer(25)
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Create a 25-meter buffer around each geometry in the GeoDataFrame using shapely's buffer method","Preserve the original CRS (EPSG:3857) in the output GeoDataFrame","Write the buffered GeoDataFrame to 'simple_buffers.geojson'"],"libraries":["geopandas","shapely"],"validation":["Verify output file 'simple_buffers.geojson' exists","Check CRS of output matches EPSG:3857","Ensure number of features equals input parcel count"]}
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 1 — rejected — cost 0.0024 USD — 28258 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf['geometry'] = gdf.geometry.buffer(25)
gdf.to_file('simple_buffers.geojson', crs='EPSG:3857')
architecture=plan-then-act
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Apply a 25-meter buffer to each geometry using shapely's buffer method","Write the buffered GeoDataFrame to 'simple_buffers.geojson' with EPSG:3857 CRS"],"libraries":["geopandas","shapely"],"validation":["Verify output file exists","Check CRS of output matches EPSG:3857","Ensure feature count matches input"]}
stage=act
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 5, in <module>
    gdf.to_file('simple_buffers.geojson', crs='EPSG:3857')
  File "/usr/local/lib/python3.11/site-packages/geopandas/geodataframe.py", line 1632, in to_file
    _to_file(self, filename, driver, schema, index, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 731, in _to_file
    _to_file_pyogrio(df, filename, driver, schema, crs, mode, metadata, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 787, in _to_file_pyogrio
    raise ValueError("Passing 'crs' is not supported with the 'pyogrio' engine.")
ValueError: Passing 'crs' is not supported with the 'pyogrio' engine.

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0020 USD — 29045 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
parcels['geometry'] = parcels.geometry.buffer(25)
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=plan-then-act
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Verify the CRS is EPSG:3857","Create a 25-meter buffer for each geometry using shapely's buffer method","Write the buffered GeoDataFrame to 'simple_buffers.geojson' with original CRS"],"libraries":["geopandas","shapely"],"validation":["Check output file exists","Validate same number of features as input","Verify CRS matches EPSG:3857","Ensure all geometries are valid"]}
stage=act
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 1 — rejected — cost 0.0033 USD — 52940 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
parcels['geometry'] = parcels.geometry.buffer(25)
parcels.to_file('simple_buffers.geojson', crs='epsg:3857')
architecture=full-multi-agent
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Create a 25-meter buffer around each geometry using shapely's buffer method","Write the buffered GeoDataFrame to 'simple_buffers.geojson' with EPSG:3857 CRS"],"libraries":["geopandas","shapely"],"validation":["Verify output file 'simple_buffers.geojson' exists","Check that output CRS matches EPSG:3857","Ensure number of features equals input parcel count"]}
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 5, in <module>
    parcels.to_file('simple_buffers.geojson', crs='epsg:3857')
  File "/usr/local/lib/python3.11/site-packages/geopandas/geodataframe.py", line 1632, in to_file
    _to_file(self, filename, driver, schema, index, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 731, in _to_file
    _to_file_pyogrio(df, filename, driver, schema, crs, mode, metadata, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 787, in _to_file_pyogrio
    raise ValueError("Passing 'crs' is not supported with the 'pyogrio' engine.")
ValueError: Passing 'crs' is not supported with the 'pyogrio' engine.

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 0 — accepted — cost 0.0037 USD — 54516 ms
# verifier: PASS — simple buffer geometry verified
# artifact: download (6171 bytes)
import geopandas as gpd

parcels = gpd.read_file('parcels.geojson')
parcels['geometry'] = parcels['geometry'].buffer(25)
parcels.to_file('simple_buffers.geojson', driver='GeoJSON')
architecture=full-multi-agent
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Create 25-meter buffers around each geometry using shapely's buffer method","Write the buffered GeoDataFrame to 'simple_buffers.geojson' preserving CRS"],"libraries":["geopandas","shapely"],"validation":["Verify output file 'simple_buffers.geojson' exists","Check CRS of output matches EPSG:3857","Ensure all input features are preserved with valid buffered geometries"]}
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

# attempt undefined — model: @cf/qwen/qwen3-30b-a3b-fp8 — exit 1 — rejected — cost 0.0050 USD — 70684 ms
# verifier: FAIL — simple buffer inputs unreadable
# no artifact produced
import geopandas as gpd

gdf = gpd.read_file('parcels.geojson')
gdf = gdf.set_crs('EPSG:3857')
gdf['geometry'] = gdf.geometry.buffer(25)
gdf.to_file('simple_buffers.geojson', crs='EPSG:3857')
architecture=full-multi-agent
stage=planner
plan={"steps":["Read 'parcels.geojson' into a GeoDataFrame using geopandas","Create 25-meter buffers around each geometry in the GeoDataFrame","Write the buffered GeoDataFrame to 'simple_buffers.geojson' with EPSG:3857 CRS"],"libraries":["geopandas","shapely"],"validation":["Verify output file exists","Check CRS of output matches EPSG:3857","Ensure number of features equals input count","Confirm geometries are valid buffers of 25 meters"]}
stage=builder
stage=auditor
auditor_output_present=true
--- execution stdout ---

--- stderr ---
Traceback (most recent call last):
  File "/tmp/arena/solution.py", line 6, in <module>
    gdf.to_file('simple_buffers.geojson', crs='EPSG:3857')
  File "/usr/local/lib/python3.11/site-packages/geopandas/geodataframe.py", line 1632, in to_file
    _to_file(self, filename, driver, schema, index, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 731, in _to_file
    _to_file_pyogrio(df, filename, driver, schema, crs, mode, metadata, **kwargs)
  File "/usr/local/lib/python3.11/site-packages/geopandas/io/file.py", line 787, in _to_file_pyogrio
    raise ValueError("Passing 'crs' is not supported with the 'pyogrio' engine.")
ValueError: Passing 'crs' is not supported with the 'pyogrio' engine.