Read STAC Tutorial Broken w/ Current Library Versions

[asmithml]

PySTAC is fairly new to me, so below are my best guesses at the causes and solutions.

Summary

The tutorial docs/tutorials/how-to-read-data-from-stac.ipynb doesn't work with current library versions. Three issues prevent the examples from running.

Issues

1. COGs section - Missing EPSG

The Planetary Computer's Landsat STAC items lack proj:epsg metadata, causing stackstac to fail.

# Original - FAILS
xr.open_dataset(landsat_item)
# ValueError: Cannot pick a common CRS...

# Fix needed
xr.open_dataset(landsat_item, epsg=32656)

2. Zarr section - Missing authentication

Azure Blob Storage now requires authentication for Daymet data.

# Original - FAILS  
xr.open_dataset(daymet_asset)
# ClientAuthenticationError: Server failed to authenticate

# Fix needed
signed_asset = pc.sign(daymet_asset)
xr.open_dataset(signed_asset)

3. Kerchunk section - Broken compatibility

CMIP6 data needs authentication, but even after signing, zarr 3.x and fsspec 2025.x have async compatibility issues that prevent opening reference files.

# After authentication, still fails with:
# ValueError: Reference-FS's target filesystem must have same value of asynchronous

Environment

• xarray: 2025.8.0, pystac: 1.13.0, xpystac: 0.2.0
• stackstac: 0.5.1, zarr: 3.1.1, fsspec: 2025.7.0

Question

Should the tutorial be updated with these fixes, or would that break compatibility with older versions? The Kerchunk issue appears unresolvable without library downgrades.

[gadomski]

Should the tutorial be updated with these fixes, or would that break compatibility with older versions? The Kerchunk issue appears unresolvable without library downgrades.

Ideally the tutorials would work with the latest versions.

[jsignell]

Yep. I can make these changes. I have kind of changed my mind on the idea of wrapping stackstac/odc-stac within xpystac anyways.