# Python Gis Ecosystem 4 Failure Diagnosis

> Sub-skill of python-gis-ecosystem: 4. FAILURE DIAGNOSIS.

- Skill: `vamseeachanta/python-gis-ecosystem-4-failure-diagnosis` (Agent Skill)
- Install (CLI): `npx skillmds@latest add vamseeachanta/python-gis-ecosystem-4-failure-diagnosis`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vamseeachanta/python-gis-ecosystem-4-failure-diagnosis/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: vamseeachanta (https://skillmd.com/u/vamseeachanta)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vamseeachanta/python-gis-ecosystem-4-failure-diagnosis

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# 4. FAILURE DIAGNOSIS

## 4. FAILURE DIAGNOSIS


| Error | Cause | Fix |
|-------|-------|-----|
| `CRS mismatch in spatial join` | Layers in different CRS | Reproject both to same CRS before join |
| `GDAL not found` / `import rasterio` fails | GDAL native libs missing | Use `conda install -c conda-forge rasterio` |
| `ValueError: No CRS set` | GeoDataFrame has no CRS | Set via `gdf = gdf.set_crs("EPSG:4326")` |
| `TopologicalError` (Shapely) | Invalid geometry | Run `gdf.geometry = gdf.geometry.buffer(0)` to fix |
| `Nodata values appear as valid data` | nodata not masked | Use `rasterio.open().read(masked=True)` |
| `MemoryError` on large raster | Full raster in RAM | Use windowed reading: `rasterio.open().block_windows()` |
| `xarray KeyError: variable` | Wrong variable name | Inspect with `ds.data_vars` |
| `fiona.errors.DriverError` | KML needs LIBKML driver | Install `fiona[all]` or use `gpd.read_file(..., driver='KML')` |

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