starting qgis from OSGeo4W shell: Couldn't load plugin 'processing'

[jakimowb]

If 'qgis-dev' has been started first, a following start of 'qgis' raises a Couldn't load plugin 'processing' error due to broken GDAL pathes (see below).

This isse was initially reported to ​https://github.com/qgis/QGIS/issues/50890

Couldn't load plugin 'processing' 

ImportError: Traceback (most recent call last):   File "F:\OSGeo4W\apps\gdal-dev\lib\site-packages\osgeo\__init__.py", line 30, in swig_import_helper     return importlib.import_module(mname)   File "F:\OSGeo4W\apps\Python39\lib\importlib\__init__.py", line 127, in import_module     return _bootstrap._gcd_import(name[level:], package, level)   File "", line 1030, in _gcd_import   File "", line 1007, in _find_and_load   File "", line 986, in _find_and_load_unlocked   File "", line 666, in _load_unlocked   File "", line 565, in module_from_spec   File "", line 1173, in create_module   File "", line 228, in _call_with_frames_removed ImportError: DLL load failed while importing _gdal: The specified module could not be found. On Windows, with Python >= 3.8, DLLs are no longer imported from the PATH. If gdalXXX.dll is in the PATH, then set the USE_PATH_FOR_GDAL_PYTHON=YES environment variable to feed the PATH into os.add_dll_directory(). 

Traceback (most recent call last):
  File "F:\OSGeo4W\apps\gdal-dev\lib\site-packages\osgeo\__init__.py", line 30, in swig_import_helper
    return importlib.import_module(mname)
  File "F:\OSGeo4W\apps\Python39\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "", line 1030, in _gcd_import
  File "", line 1007, in _find_and_load
  File "", line 986, in _find_and_load_unlocked
  File "", line 666, in _load_unlocked
  File "", line 565, in module_from_spec
  File "", line 1173, in create_module
  File "", line 228, in _call_with_frames_removed
ImportError: DLL load failed while importing _gdal: The specified module could not be found.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 401, in loadPlugin
    __import__(packageName)
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W/apps/qgis/./python/plugins\processing\__init__.py", line 26, in 
    from processing.tools.general import *  # NOQA
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W/apps/qgis/./python/plugins\processing\tools\general.py", line 32, in 
    from processing.core.Processing import Processing
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W/apps/qgis/./python/plugins\processing\core\Processing.py", line 58, in 
    from processing.algs.qgis.QgisAlgorithmProvider import QgisAlgorithmProvider  # NOQA
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W/apps/qgis/./python/plugins\processing\algs\qgis\QgisAlgorithmProvider.py", line 49, in 
    from .HypsometricCurves import HypsometricCurves
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W/apps/qgis/./python/plugins\processing\algs\qgis\HypsometricCurves.py", line 27, in 
    from osgeo import gdal, ogr, osr
  File "F:\OSGeo4W/apps/qgis/./python\qgis\utils.py", line 888, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "F:\OSGeo4W\apps\gdal-dev\lib\site-packages\osgeo\__init__.py", line 46, in 
    _gdal = swig_import_helper()
  File "F:\OSGeo4W\apps\gdal-dev\lib\site-packages\osgeo\__init__.py", line 42, in swig_import_helper
    raise ImportError(traceback_string + '\n' + msg)
ImportError: Traceback (most recent call last):
  File "F:\OSGeo4W\apps\gdal-dev\lib\site-packages\osgeo\__init__.py", line 30, in swig_import_helper
    return importlib.import_module(mname)
  File "F:\OSGeo4W\apps\Python39\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "", line 1030, in _gcd_import
  File "", line 1007, in _find_and_load
  File "", line 986, in _find_and_load_unlocked
  File "", line 666, in _load_unlocked
  File "", line 565, in module_from_spec
  File "", line 1173, in create_module
  File "", line 228, in _call_with_frames_removed
ImportError: DLL load failed while importing _gdal: The specified module could not be found.

On Windows, with Python >= 3.8, DLLs are no longer imported from the PATH.
If gdalXXX.dll is in the PATH, then set the USE_PATH_FOR_GDAL_PYTHON=YES environment variable
to feed the PATH into os.add_dll_directory().


Python version: 3.9.5 (tags/v3.9.5:0a7dcbd, May  3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)] 
QGIS version: 3.28.0-Firenze Firenze, ed3ad0430f3 

[jef]

Run the executable qgis{,-ltr,dev}-bin.exe instead of the batch file (like the shortcut would)

[jakimowb]

Thanks for your reply. Yes indeed, calling qgis.exe or qgis-dev.exe directly, e.g. from windows explorer, avoids the error (similar to restarting the OSGeo4W shell). So the entire issue may have a low priority only.

Otherwise, I'd expect that each bat/exe that is listed by o-help can be run in the OSGeo4W shell no matter which other bat/exe was executed before. At least in the OSGeo4W environment that I installed a couple of minutes ago (folder F:\OSGeo4W-2) neither qgis.exe nor qgis-dev.exe is available (but the *.bat listed by o-help).

F:\OSGeo4W-2>o-help
                   -={ OSGeo4W Shell Commands }=-
  applygeo                                bgspawn
  brotli                                  curl
  dllupdate                               gdaladdo
  gdalbuildvrt                            gdaldem
  gdalenhance                             gdalinfo
  gdallocationinfo                        gdalmanage
  gdalmdiminfo                            gdalmdimtranslate
  gdalsrsinfo                             gdaltindex
  gdaltransform                           gdalwarp
  gdal_contour                            gdal_create
  gdal_grid                               gdal_rasterize
  gdal_translate                          gdal_viewshed
  geotifcp                                getspecialfolder
  gnmanalyse                              gnmmanage
  iconv                                   listgeo
  makegeo                                 nearblack
  ogr2ogr                                 ogrinfo
  ogrlineref                              ogrtindex
  osgeo4w-setup                           pdal
  pg_dump                                 pg_dumpall
  pg_restore                              psql
  python                                  python3
  pythonw                                 pythonw3
  qgis-bin                                qgis-dev-bin
  sqlite3                                 textreplace
  xmlcatalog                              xmllint
  xxmklink                                gdal-dev-env
  gdal-dev-py-env                         o-help
  o4w_env                                 python-qgis-dev
  python-qgis                             qgis-designer
  qgis-dev-designer                       qgis-dev
  qgis                                    qgis_process-qgis-dev
  qgis_process-qgis                       setup

GDAL 3.6.0, released 2022/11/06

F:\OSGeo4W-2>where qgis
F:\OSGeo4W-2\bin\qgis.bat

F:\OSGeo4W-2>where qgis-dev
F:\OSGeo4W-2\bin\qgis-dev.bat

F:\OSGeo4W-2>where qgis.exe
INFO: Could not find files for the given pattern(s).

F:\OSGeo4W-2>where qgis-dev.exe
INFO: Could not find files for the given pattern(s).

[jef]

qgis-bin.exe, qgis-ltr-bin.exe, qgis-dev-bin.exe

[jef]

You can also as set PYTHONPATH= to etc/ini/python3.bat to use the batch files.