Make consistent use of Python targets and variables in CMake

cmake/modules/DuneAddPybind11Module.cmake

@@ -78,15 +78,12 @@ function(dune_add_pybind11_module)
 
   # force '.so' as library suffix on macOS due to a problem in Python
   # https://stackoverflow.com/questions/2488016/how-to-make-python-load-dylib-on-osx
-  # and add -undefined dynamic_lookup flag to linker
-  # https://pybind11.readthedocs.io/en/stable/compiling.html#building-manually
   if (APPLE)
     set_target_properties(${PYBIND11_MODULE_NAME} PROPERTIES SUFFIX ".so")
-    target_link_options(${PYBIND11_MODULE_NAME} PRIVATE -undefined dynamic_lookup)
   endif()
 
   target_compile_definitions(${PYBIND11_MODULE_NAME} PRIVATE ${PYBIND11_MODULE_COMPILE_DEFINITIONS})
-  target_link_libraries(${PYBIND11_MODULE_NAME} PUBLIC Dune::Common)
+  target_link_libraries(${PYBIND11_MODULE_NAME} PUBLIC Dune::Common Python3::Module)
   dune_target_enable_all_packages(${PYBIND11_MODULE_NAME})
 
   if(PYBIND11_MODULE_EXCLUDE_FROM_ALL)

cmake/modules/DunePythonCommonMacros.cmake

@@ -105,7 +105,7 @@ if(Python3_Interpreter_FOUND)
   ##### Python bindings specific part begin ################
   # first we test if all requirements are satisfied, if not, Python bindings are
   # disabled and the user gets an informative message explaining why
-  if((DUNE_ENABLE_PYTHONBINDINGS) AND (NOT Python3_INCLUDE_DIRS))
+  if((DUNE_ENABLE_PYTHONBINDINGS) AND (NOT ${Python3_Development.Module_FOUND}))
     message(STATUS "Python bindings disabled")
     message(NOTICE
       "   ----------------------------------------------------------------------------------------\n"

cmake/modules/DunePythonInstallPackage.cmake

@@ -516,7 +516,8 @@ function(dune_python_configure_package)
 
     # Add a custom target that globally installs this package if requested
     if (NOT PYPKGCONF_INSTALL_TARGET)
-      string(REPLACE "/" "_" PYPKGCONF_INSTALL_TARGET "install_python_${CMAKE_CURRENT_SOURCE_DIR}_${PYPKGCONF_PATH}")
+      string(MD5 path_hash "${PYCONFBIND_FULLPATH}")
+      set(PYPKGCONF_INSTALL_TARGET "install_python_${path_hash}")
     endif()
 
     # TODO this creates an egg-info folder in the source directory
@@ -631,11 +632,12 @@ function(dune_python_configure_bindings)
     message(FATAL_ERROR "dune_python_configure_bindings: ${PYCONFBIND_FULLPATH} does not exists")
   endif()
 
+  string(MD5 path_hash "${PYCONFBIND_FULLPATH}")
   dune_python_configure_package(
     PATH ${PYCONFBIND_FULLPATH}
     ADDITIONAL_PIP_PARAMS ${PYCONFBIND_ADDITIONAL_PIP_PARAMS}
     RESULT PYTHON_PACKAGE_FAILED
-    INSTALL_TARGET install_python_package_${PYCONFBIND_PACKAGENAME}
+    INSTALL_TARGET install_python_package_${path_hash}
   )
 
   # we could actually add metadata even if the configuration of the venv
@@ -648,7 +650,7 @@ function(dune_python_configure_bindings)
     dune_link_dune_py(
       PATH ${CMAKE_CURRENT_BINARY_DIR}/${PYCONFBIND_PATH}
       PACKAGENAME ${PYCONFBIND_PACKAGENAME}
-      INSTALL_TARGET install_python_package_${PYCONFBIND_PACKAGENAME}
+      INSTALL_TARGET install_python_package_${path_hash}
       CMAKE_METADATA_FLAGS ${PYCONFBIND_CMAKE_METADATA_FLAGS}
     )
   else()

cmake/modules/DunePythonVirtualenv.cmake

@@ -242,7 +242,8 @@ if(DUNE_PYTHON_USE_VENV)
   endif()
 
   # Also store the virtual env interpreter directly
-  set(DUNE_PYTHON_VIRTUALENV_EXECUTABLE ${DUNE_PYTHON_VIRTUALENV_PATH}/bin/python)
+  set(DUNE_PYTHON_VIRTUALENV_EXECUTABLE ${DUNE_PYTHON_VIRTUALENV_PATH}/bin/python
+    CACHE INTERNAL "Python virtual environment executable used by Dune")
 
   # Write a symlink for activation of the environment into all the
   # build directories of the Dune stack
@@ -312,7 +313,7 @@ if(DUNE_PYTHON_USE_VENV)
   endif()
 
   # if pip was not found before then we can set it here since it was now found
-  set(DUNE_PYTHON_pip_FOUND ON)
+  set(DUNE_PYTHON_pip_FOUND ON CACHE INTERNAL "Whether dune has found python pip")
 
   # install setuptools into the venv (needed to find dependencies later on)
   dune_execute_process(COMMAND ${DUNE_PYTHON_VIRTUALENV_EXECUTABLE} -m pip install

dune/python/test/CMakeLists.txt

@@ -14,18 +14,20 @@ dune_python_add_test(NAME tuplevectortest
                      LABELS quick
 )
 
-dune_add_test(SOURCES test_embed1.cc
-              LINK_LIBRARIES ${DUNE_LIBS} ${Python3_LIBRARIES}
-              LABELS quick
-              COMMAND ${CMAKE_BINARY_DIR}/run-in-dune-env
-              CMD_ARGS $<TARGET_FILE:test_embed1>
-)
-target_compile_definitions(test_embed1 PRIVATE PYTHON_INTERPRETER=L"${DUNE_PYTHON_VIRTUALENV_EXECUTABLE}")
+if(TARGET Python3::Python)
+    dune_add_test(SOURCES test_embed1.cc
+                LINK_LIBRARIES ${DUNE_LIBS} Python3::Python
+                LABELS quick
+                COMMAND ${CMAKE_BINARY_DIR}/run-in-dune-env
+                CMD_ARGS $<TARGET_FILE:test_embed1>
+    )
+    target_compile_definitions(test_embed1 PRIVATE PYTHON_INTERPRETER=L"${DUNE_PYTHON_VIRTUALENV_EXECUTABLE}")
 
-dune_add_test(SOURCES test_embed2.cc
-              LINK_LIBRARIES ${DUNE_LIBS} ${Python3_LIBRARIES}
-              LABELS quick
-              COMMAND ${CMAKE_BINARY_DIR}/run-in-dune-env
-              CMD_ARGS $<TARGET_FILE:test_embed2>
-)
-target_compile_definitions(test_embed2 PRIVATE PYTHON_INTERPRETER=L"${DUNE_PYTHON_VIRTUALENV_EXECUTABLE}")
+    dune_add_test(SOURCES test_embed2.cc
+                LINK_LIBRARIES ${DUNE_LIBS} Python3::Python
+                LABELS quick
+                COMMAND ${CMAKE_BINARY_DIR}/run-in-dune-env
+                CMD_ARGS $<TARGET_FILE:test_embed2>
+    )
+    target_compile_definitions(test_embed2 PRIVATE PYTHON_INTERPRETER=L"${DUNE_PYTHON_VIRTUALENV_EXECUTABLE}")
+endif()