Error when installing with Dockerfile

[ondics]

My Dockerfile (already added the : @v2.0.0 tag but there's no difference):

FROM openknowledge/ckan-base:2.9
...
# Spatial Extension
RUN pip install -e git+https://github.com/ckan/ckanext-spatial.git@v2.0.0#egg=ckanext-spatial && \
    pip install -r $SRC_DIR/ckanext-spatial/pip-requirements.txt

fails when building with these messages:

388.8   Installing backend dependencies: started
391.5   Installing backend dependencies: finished with status 'done'
391.5   Preparing metadata (pyproject.toml): started
392.6   Preparing metadata (pyproject.toml): finished with status 'done'
392.8 Collecting pyproj==2.6.1 (from -r /srv/app/src/ckanext-spatial/pip-requirements.txt (line 3))
392.8   Downloading pyproj-2.6.1.tar.gz (528 kB)
392.8      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 528.2/528.2 kB 30.1 MB/s eta 0:00:00
393.0   Installing build dependencies: started
400.0   Installing build dependencies: finished with status 'done'
400.0   Getting requirements to build wheel: started
403.7   Getting requirements to build wheel: finished with status 'error'
403.7   error: subprocess-exited-with-error
403.7
403.7   × Getting requirements to build wheel did not run successfully.
403.7   │ exit code: 1
403.7   ╰─> [53 lines of output]
403.7       <string>:8: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
403.7
403.7       Error compiling Cython file:
403.7       ------------------------------------------------------------
403.7       ...
403.7           bint free_context_on_error,
403.7       ) except *:
403.7           """
403.7           Setup the context for pyproj
403.7           """
403.7           proj_log_func(context, NULL, pyproj_log_function)
403.7                                        ^
403.7       ------------------------------------------------------------
403.7
403.7       pyproj/_datadir.pyx:40:33: Cannot assign type 'void (void *, int, const char *) except *' to 'PJ_LOG_FUNCTION'. Exception values are incompatible. Suggest adding 'noexcept' to type 'void (void *, int, const char *) except *'.
403.7
403.7       Error compiling Cython file:
403.7       ------------------------------------------------------------
403.7       ...
403.7                   proj_context_destroy(context)
403.7               raise

Python: 3.8.15
CKAN: 2.9.9

What's going wrong here? How to proceed?