Coordinates.from_xindex(RasterIndex) produces scalar coords with wrong shape after chunked nearest spatial selection

[hrodmn]

Hi rasterix 👋 - thanks for building this awesome package! I found a small bug after bringing rasterix into lazycogs. Maybe this is a known limitation and I am not using it correctly.

Using rasterix.RasterIndex via xarray.Coordinates.from_xindex(index) appears to break a chunked scalar spatial selection path in xarray.

A pattern like:

da = da.chunk(time=1).sel(x=..., y=..., method="nearest").compute()

fails when x and y come from Coordinates.from_xindex(RasterIndex(...)).

What seems to happen:

• after sel(x=..., y=..., method="nearest"), x and y become scalar coords
• during compute(), those lazy scalar coords materialize as shape (1,) instead of ()
• xarray then raises a shape mismatch, e.g.:

ValueError: replacement data must match the Variable's shape. replacement data has shape (1,); Variable has shape ()

Workaround on our side:

• keep the RasterIndex attached for indexing behavior
• eagerly materialize the x/y coordinate variables instead of using the lazy coord variables from Coordinates.from_xindex(index)

Question:

• is this a known limitation/bug in rasterix’s xarray integration?
• should scalar coord materialization after chunked selection be handled differently in RasterIndex / create_variables() / from_xindex usage?