ModuleNotFoundError: No module named 'ckanext.spatial' on extension installation

Try to install ckanext-spatial extension I always get the same error. Python version 3.8. Ckan version 2.10.1

Also try install from master branch the same error.

(default) [ckan-user@ckan2-10 src]$ pip install -e "git+https://github.com/ckan/ckanext-spatial.git@v2.1.1#egg=ckanext-spatial"
WARNING: Ignoring invalid distribution -kanext-latvian-theme-v2 (/usr/lib/ckan/default/lib/python3.8/site-packages)
Obtaining ckanext-spatial from git+https://github.com/ckan/ckanext-spatial.git@v2.1.1#egg=ckanext-spatial
Cloning https://github.com/ckan/ckanext-spatial.git (to revision v2.1.1) to ./ckanext-spatial
Running command git clone --filter=blob:none --quiet https://github.com/ckan/ckanext-spatial.git /usr/lib/ckan/default/src/ckanext-spatial
Running command git checkout -q 938308469892e4bcf7389cb4adee5ccdd5a0ccca
Resolved https://github.com/ckan/ckanext-spatial.git to commit 938308469892e4bcf7389cb4adee5ccdd5a0ccca
Running command git submodule update --init --recursive -q
Installing build dependencies ... done
Checking if build backend supports build_editable ... done
Getting requirements to build editable ... error
error: subprocess-exited-with-error

× Getting requirements to build editable did not run successfully.
│ exit code: 1
╰─> [19 lines of output]
Traceback (most recent call last):
File "/usr/lib/ckan/default/lib64/python3.8/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in
main()
File "/usr/lib/ckan/default/lib64/python3.8/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
json_out['return_val'] = hook(**hook_input['kwargs'])
File "/usr/lib/ckan/default/lib64/python3.8/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 132, in get_requires_for_build_editable
return hook(config_settings)
File "/tmp/pip-build-env-0aq07msc/overlay/lib/python3.8/site-packages/setuptools/build_meta.py", line 458, in get_requires_for_build_editable
return self.get_requires_for_build_wheel(config_settings)
File "/tmp/pip-build-env-0aq07msc/overlay/lib/python3.8/site-packages/setuptools/build_meta.py", line 327, in get_requires_for_build_wheel
return self._get_build_requires(config_settings, requirements=[])
File "/tmp/pip-build-env-0aq07msc/overlay/lib/python3.8/site-packages/setuptools/build_meta.py", line 297, in _get_build_requires
self.run_setup()
File "/tmp/pip-build-env-0aq07msc/overlay/lib/python3.8/site-packages/setuptools/build_meta.py", line 497, in run_setup
super().run_setup(setup_script=setup_script)
File "/tmp/pip-build-env-0aq07msc/overlay/lib/python3.8/site-packages/setuptools/build_meta.py", line 313, in run_setup
exec(code, locals())
File "", line 2, in
ModuleNotFoundError: No module named 'ckanext.spatial'
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build editable did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.

Start by reproducing the reported editable installation command for ckanext-spatial v2.1.1 with Python 3.8 and CKAN 2.10.1, then inspect the build output around the ModuleNotFoundError for ckanext.spatial. Done means the extension installs successfully from the tagged or master revision without this error.

Written by the indexing model from the issue text.