macpython,manylinux: Use SKBUILD_CMAKE_INSTALL_PREFIX for PY_SITE_PACKAGES

Required for skbuild 0.7.0 and newer to address:

Traceback (most recent call last):
  File "setup.py", line 62, in <module>
    install_requires=[
  File "/opt/python/cp37-cp37m/lib/python3.7/site-packages/skbuild/setuptools_wrap.py", line 558, in setup
    cmake_source_dir, skbuild_kw['cmake_install_dir'])
  File "/opt/python/cp37-cp37m/lib/python3.7/site-packages/skbuild/setuptools_wrap.py", line 686, in _classify_installed_files
    install_root, to_platform_path(path)))
skbuild.exceptions.SKBuildError:
  CMake-installed files must be within the project root.
    Project Root  : /work/_skbuild/linux-x86_64-3.7/cmake-install
    Violating File: _skbuild/cmake-install/itkConfig.py

Co-authored-by: Jean-Christophe Fillion-Robin <[email protected]>

Author: thewtex

scripts/internal/manylinux-build-wheels.sh

@@ -28,7 +28,7 @@ SINGLE_WHEEL=0
 
 # Compile wheels re-using standalone project and archive cache
 for PYBIN in "${PYBINARIES[@]}"; do
-    PYTHON_EXECUTABLE=${PYBIN}/python
+    export PYTHON_EXECUTABLE=${PYBIN}/python
     PYTHON_INCLUDE_DIR=$( find -L ${PYBIN}/../include/ -name Python.h -exec dirname {} \; )
 
     echo ""
@@ -43,6 +43,7 @@ for PYBIN in "${PYBINARIES[@]}"; do
     source_path=/work/standalone-${ARCH}-build/ITK-source
     build_path=/work/ITK-$(basename $(dirname ${PYBIN}))-manylinux1_${ARCH}
     SETUP_PY_CONFIGURE="${script_dir}/../setup_py_configure.py"
+    SKBUILD_CMAKE_INSTALL_PREFIX=$(${PYTHON_EXECUTABLE} -c "from skbuild.constants import CMAKE_INSTALL_DIR; print(CMAKE_INSTALL_DIR)")
 
     # Clean up previous invocations
     rm -rf ${build_path}
@@ -93,7 +94,7 @@ for PYBIN in "${PYBINARIES[@]}"; do
           -DWRAP_ITK_INSTALL_COMPONENT_IDENTIFIER:STRING=PythonWheel \
           -DWRAP_ITK_INSTALL_COMPONENT_PER_MODULE:BOOL=ON \
           -DITK_WRAP_unsigned_short:BOOL=ON \
-          -DPY_SITE_PACKAGES_PATH:PATH=${script_dir}/../../_skbuild/cmake-install \
+          -DPY_SITE_PACKAGES_PATH:PATH=${SKBUILD_CMAKE_INSTALL_PREFIX} \
           -DITK_LEGACY_SILENT:BOOL=ON \
           -DITK_WRAP_PYTHON:BOOL=ON \
           -DITK_WRAP_PYTHON_LEGACY:BOOL=OFF \

scripts/macpython-build-wheels.sh

@@ -63,7 +63,7 @@ SINGLE_WHEEL=0
 # Compile wheels re-using standalone project and archive cache
 for VENV in "${VENVS[@]}"; do
     py_mm=$(basename ${VENV})
-    PYTHON_EXECUTABLE=${VENV}/bin/python
+    export PYTHON_EXECUTABLE=${VENV}/bin/python
     PYTHON_INCLUDE_DIR=$( find -L ${MACPYTHON_PY_PREFIX}/${py_mm}/include -name Python.h -exec dirname {} \; )
 
     echo ""
@@ -80,6 +80,7 @@ for VENV in "${VENVS[@]}"; do
     source_path=${SCRIPT_DIR}/../standalone-build/ITK-source
     build_path="${SCRIPT_DIR}/../ITK-${py_mm}-macosx_x86_64"
     SETUP_PY_CONFIGURE="${script_dir}/setup_py_configure.py"
+    SKBUILD_CMAKE_INSTALL_PREFIX=$(${PYTHON_EXECUTABLE} -c "from skbuild.constants import CMAKE_INSTALL_DIR; print(CMAKE_INSTALL_DIR)")
 
     # Clean up previous invocations
     rm -rf ${build_path}
@@ -130,7 +131,7 @@ for VENV in "${VENVS[@]}"; do
           -DPYTHON_LIBRARY:FILEPATH=${PYTHON_LIBRARY} \
           -DWRAP_ITK_INSTALL_COMPONENT_IDENTIFIER:STRING=PythonWheel \
           -DWRAP_ITK_INSTALL_COMPONENT_PER_MODULE:BOOL=ON \
-          -DPY_SITE_PACKAGES_PATH:PATH=${SCRIPT_DIR}/../_skbuild/cmake-install \
+          -DPY_SITE_PACKAGES_PATH:PATH=${SKBUILD_CMAKE_INSTALL_PREFIX} \
           -DITK_LEGACY_SILENT:BOOL=ON \
           -DITK_WRAP_PYTHON:BOOL=ON \
           -DITK_WRAP_PYTHON_LEGACY:BOOL=OFF \