python_gdal_libs.md

Below is a bash session, in a docker container running GDAL docker/ubuntu-small. In the container in 'builder' mode I've run

cmake .. -DCMAKE_BUILD_TYPE=Debug
sudo cmake --build .  --target install 

I start python3, which is 3.10.6 - and GDAL has placed the osgeo libs into '/usr/local/lib/python3/dist-packages', but python is only looking in '/usr/local/lib/python3.10/dist-packages'

Is there a config step with cmake, or a subsequent step with python config that I should be doing? (do I just symlink the libs??)

root@53837d4fa20e:/gdal-source/build2# python3
Python 3.10.6 (main, Nov 14 2022, 16:10:14) [GCC 11.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from osgeo import gdal
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'osgeo'
>>>
[3]+  Stopped                 python3


ls /usr/lib/python3/dist-packages/
_distutils_hack  numpy  numpy-1.21.5.egg-info  pkg_resources  setuptools  setuptools-59.6.0.egg-info

ls /usr/local/lib/python3/dist-packages/
GDAL-3.7.0.egg-info  osgeo  osgeo_utils


python3
Python 3.10.6 (main, Nov 14 2022, 16:10:14) [GCC 11.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/usr/lib/python310.zip', '/usr/lib/python3.10', '/usr/lib/python3.10/lib-dynload', '/usr/local/lib/python3.10/dist-packages', '/usr/lib/python3/dist-packages']
>>>

Details above were posted to back up this question on gdal-dev: https://lists.osgeo.org/pipermail/gdal-dev/2023-March/057000.html

The answer is to not use the implicit value for CMAKE_INSTALL_PREFIX which is /usr/local, set it to /usr:

cmake .. -DCMAKE_INSTALL_PREFIX=/usr 
cmake --build . --parallel 31  --target install 

thanks Even Rouault https://lists.osgeo.org/pipermail/gdal-dev/2023-March/057001.html

all working now without extra cruft. For reference we can do the implicit one cmake .. ; cmake --build . etc by following up with

sudo ldconfig ## because /usr/local/lib/python3/dist-packages/ has just been created by GDAL and didn't exist before
export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3/dist-packages

but then you have extra stuff going on so let's avoid it