3.16.0 build fails with -DWITH_BINDINGS=no && WITH_QGIS_PROCESS=yes in target `qgis_process`

[a17r]

Even though there is a conditional to be found inside src/process/CMakeLists.txt...

IF (WITH_BINDINGS)
  TARGET_LINK_LIBRARIES(qgis_process qgispython)
ENDIF(WITH_BINDINGS)

...this doesn't build as main.cpp and qgsprocess.cpp unconditionally include qgsprocess.h which then unconditionally includes qgspythonrunner.h and qgspythonutils.h.

Used build options:

cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/usr -DQGIS_MANUAL_SUBDIR=share/man/ -DQGIS_LIB_SUBDIR=lib64 \
-DQGIS_PLUGIN_SUBDIR=lib64/qgis -DQWT_INCLUDE_DIR=/usr/include/qwt6 -DQWT_LIBRARY=/usr/lib64/libqwt6-qt5.so \
-DPEDANTIC=OFF -DUSE_CCACHE=OFF -DWITH_ANALYSIS=ON -DWITH_APIDOC=OFF -DWITH_GUI=ON -DWITH_INTERNAL_MDAL=ON \
-DWITH_QSPATIALITE=ON -DENABLE_TESTS=OFF -DWITH_3D=no -DWITH_GEOREFERENCER=no -DWITH_GRASS7=no \
-DCMAKE_DISABLE_FIND_PACKAGE_HDF5=ON -DWITH_SERVER=no -DCMAKE_DISABLE_FIND_PACKAGE_NetCDF=ON -DUSE_OPENCL=no \
-DWITH_ORACLE=no -DWITH_QWTPOLAR=no -DWITH_POSTGRESQL=yes -DWITH_BINDINGS=no -DWITH_CUSTOM_WIDGETS=no \
-DWITH_QUICK=yes -DWITH_QTWEBKIT=OFF

Error snippet:

In file included from src/process/qgis_process_autogen/EWIEGA46WW/../../../../../qgis-3.16.0/src/process/qgsprocess.h:22,
                 from src/process/qgis_process_autogen/EWIEGA46WW/moc_qgsprocess.cpp:10,
                 from src/process/qgis_process_autogen/mocs_compilation.cpp:2:
qgis-3.16.0/src/python/qgspythonutils.h:22:10: fatal error: qgis_python.h: No such file or directory
   22 | #include "qgis_python.h"
      |          ^~~~~~~~~~~~~~~
compilation terminated.

[3nids]

@nyalldawson is process supposed to work without Python? i.e. shall we make the includes conditionals and see if it builds or return an error in CMake if there is no Python and process is enabled?

[nyalldawson]

@3nids

is process supposed to work without Python?

Yes, it should work