CMake: Fix Python Install Directory (#1393)

Fix regressions in 0.15.0 that showed up during packaging.

Author: ax3l

CMakeLists.txt

@@ -680,7 +680,7 @@ if(openPMD_HAVE_ADIOS1)
                 COMPILE_PDB_NAME_${CFG_UPPER} openPMD.ADIOS1.Serial
                 ARCHIVE_OUTPUT_DIRECTORY_${CFG_UPPER} ${openPMD_ARCHIVE_OUTPUT_DIRECTORY}/${CFG}
                 LIBRARY_OUTPUT_DIRECTORY_${CFG_UPPER} ${openPMD_LIBRARY_OUTPUT_DIRECTORY}/${CFG}
-                RUNTIME_OUTPUT_DIRECTORY_${CFG_UPPER} ${CMAKE_PYTHON_OUTPUT_DIRECTORY}/${CFG}
+                RUNTIME_OUTPUT_DIRECTORY_${CFG_UPPER} ${openPMD_RUNTIME_OUTPUT_DIRECTORY}/${CFG}
                 PDB_OUTPUT_DIRECTORY_${CFG_UPPER} ${openPMD_PDB_OUTPUT_DIRECTORY}/${CFG}
                 COMPILE_PDB_OUTPUT_DIRECTORY_${CFG_UPPER} ${openPMD_COMPILE_PDB_OUTPUT_DIRECTORY}/${CFG}
             )
@@ -875,10 +875,10 @@ if(openPMD_HAVE_PYTHON)
             "${CMAKE_INSTALL_LIBDIR}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages"
         )
     endif()
-    # Location for installed python package
-    set(openPMD_INSTALL_PYTHONDIR "${openPMD_INSTALL_PYTHONDIR_DEFAULT}")
-    # Build directory for python modules
-    set(openPMD_PYTHON_OUTPUT_DIRECTORY "${openPMD_BINARY_DIR}/${openPMD_INSTALL_PYTHONDIR}")
+    set(openPMD_INSTALL_PYTHONDIR "${openPMD_INSTALL_PYTHONDIR_DEFAULT}"
+        CACHE STRING "Location for installed python package")
+    set(openPMD_PYTHON_OUTPUT_DIRECTORY "${openPMD_BINARY_DIR}/${openPMD_INSTALL_PYTHONDIR}"
+        CACHE STRING "Build directory for python modules")
     set_target_properties(openPMD.py PROPERTIES
         ARCHIVE_OUTPUT_NAME openpmd_api_cxx
         LIBRARY_OUTPUT_NAME openpmd_api_cxx

setup.py

@@ -47,7 +47,7 @@ def build_extension(self, ext):
             '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=' +
             os.path.join(extdir, "openpmd_api"),
             # '-DCMAKE_RUNTIME_OUTPUT_DIRECTORY=' + extdir,
-            '-DCMAKE_PYTHON_OUTPUT_DIRECTORY=' + extdir,
+            '-DopenPMD_PYTHON_OUTPUT_DIRECTORY=' + extdir,
             '-DPython_EXECUTABLE=' + sys.executable,
             '-DopenPMD_USE_PYTHON:BOOL=ON',
             # variants