Seeding with polygon coverages fails due to upgraded Shapely

[jipeream]

What is the bug or the crash?

Mapproxy uses GDAL/Shapely to deal with coverages when seeding, but fails with Shapely>=2.0 (and I believe >=1.8) as Multipolygons are now iterated in a different way in this library:

File "/usr/local/lib/python3.11/site-packages/mapproxy/util/geom.py", line 237, in transform_multipolygon
for polygon in multipolygon:
TypeError: 'MultiPolygon' object is not iterable

There is already an open issue/PR in Mapproxy:
mapproxy/mapproxy#611
https://github.com/mapproxy/mapproxy/pull/749/files

In the meantime, forcing pip install Shapely==1.7.1 should work (in fact it does).

As an alternative, we can wait until Mapproxy corrects this issue...

Steps to reproduce the issue

Any mapproxy-seed using wkt polygon coverages will fail with the following error:

  File "/usr/local/lib/python3.11/site-packages/mapproxy/util/geom.py", line 222, in transform_geometry
    result = transform_multipolygon(transf, geometry)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/mapproxy/util/geom.py", line 237, in transform_multipolygon
    for polygon in multipolygon:
TypeError: 'MultiPolygon' object is not iterable

Versions

MapProxy 1.16.0
Shapely 2.0

Additional context

No response

[NyakudyaA]

@jipeream Thanks, Can you raise a PR here and make sure to add a TODO in the code with a link to the upstream issue so that we can revert the temporary fix when it's fixed upstream,
Alternatively, we can try to release v2.0

[jipeream]

Sure!!! Not a big deal, but It would be muy first contribution ever. I will use an env variable, as you do with MapProxy itself, so that it will be easier to revert. El sáb, 21 oct 2023 11:17, mazano ***@***.***> escribió:

…

@jipeream <https://github.com/jipeream> Thanks, Can you raise a PR here and make sure to add a TODO in the code with a link to the upstream issue so that we can revert the temporary fix when it's fixed upstream — Reply to this email directly, view it on GitHub <#63 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AD2JQNLELNHQDJWDXGKJ6PLYAOHKJAVCNFSM6AAAAAA6J7N24SVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTONZTG4ZDQNJRHA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[jipeream]

Two questions:

1. Do you prefer
   ARG SHAPELY_VERSION='==1.7.1'
   or
   ARG SHAPELY_VERSION='' and a note to use '--build-arg SHAPELY_VERSION="==1.7.1"' ?

2. Which branch should I ask my PR to be merged in?

[NyakudyaA]

Maybe we can rather add those installed packages in https://github.com/kartoza/docker-mapproxy/blob/master/Dockerfile#L26 to a requirements file and just install them with pip3 install requirements.txt the new could just add into the readme a comment mentioning that you can specify pinned versions in requirements.txt
do the PR against master