From 3f42f88a8a5ab5140d01b70690ad479cb374795f Mon Sep 17 00:00:00 2001
From: Max Smolens <max.smolens@kitware.com>
Date: Thu, 3 Sep 2015 09:42:57 -0400
Subject: [PATCH] Fix OS X build when CMAKE_BUILD_WITH_INSTALL_RPATH is enabled

When building Python 2.7.4+, python is run from the build tree as part of the
build process.  When BUILD_SHARED and CMAKE_BUILD_WITH_INSTALL_RPATH are enabled
the python executable is unable to find the shared library.  The build fails
with an error like:

    [100%] Relocate _sysconfigdata.py and update pybuilddir.txt
    dyld: Library not loaded: /path/to/python-install/lib/libpython2.7.dylib
      Referenced from: /path/to/python-build/bin/python
      Reason: image not found
    /bin/sh: line 1: 12570 Trace/BPT trap          /path/to/python-build/bin/python -E -S -m sysconfig --generate-posix-vars
    make[2]: *** [bin/pybuilddir.txt] Error 133
    make[1]: *** [CMakeBuild/python/CMakeFiles/update_sysconfig.dir/all] Error 2
    make: *** [all] Error 2

The same error shows when running the tests.

This commit sets the DYLD_LIBRARY_PATH so that the executable finds the shared
library when building and when running the tests.

[cmake -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON -DBUILD_SHARED=ON]
---
 CMakeLists.txt              | 6 +++++-
 cmake/python/CMakeLists.txt | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index af372be63..6487ac420 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -319,11 +319,15 @@ if(BUILD_TESTING)
     set(TESTOPTS -l ${EXTRATESTOPTS})
     set(TESTPROG ${CMAKE_BINARY_DIR}/${PYTHONHOME}/test/regrtest.py)
     set(TESTPYTHONOPTS )
+    set(TESTPYTHONWRAPPER )
+    if(APPLE AND BUILD_SHARED)
+        set(TESTPYTHONWRAPPER env DYLD_LIBRARY_PATH=${CMAKE_BINARY_DIR}/${LIBPYTHON_LIBDIR})
+    endif()
     set(TESTPYTHON $<TARGET_FILE:python> -Wd -3 -E -tt ${TESTPYTHONOPTS})
 
     include(cmake/UnitTests.cmake)
     foreach(unittest ${unittests})
-      add_test(NAME ${unittest} COMMAND ${TESTPYTHON} ${TESTPROG} ${TESTOPTS} ${unittest})
+      add_test(NAME ${unittest} COMMAND ${TESTPYTHONWRAPPER} ${TESTPYTHON} ${TESTPROG} ${TESTOPTS} ${unittest})
     endforeach(unittest)
 endif(BUILD_TESTING)
 
diff --git a/cmake/python/CMakeLists.txt b/cmake/python/CMakeLists.txt
index acd36d2e5..0638704e1 100644
--- a/cmake/python/CMakeLists.txt
+++ b/cmake/python/CMakeLists.txt
@@ -24,9 +24,13 @@ install(TARGETS python EXPORT PythonTargets RUNTIME DESTINATION ${BIN_INSTALL_DI
 
 if(UNIX AND PY_VERSION VERSION_GREATER "2.7.4")
     # Setup landmark allowing to run the interpreter from a build tree. See 'getpath.c' for details.
+    set(PYTHON_WRAPPER_COMMAND )
+    if(APPLE AND BUILD_SHARED)
+        set(PYTHON_WRAPPER_COMMAND env DYLD_LIBRARY_PATH="${CMAKE_BINARY_DIR}/${LIBPYTHON_LIBDIR}")
+    endif()
     add_custom_command(
         OUTPUT ${BIN_BUILD_DIR}/pybuilddir.txt ${EXTENSION_BUILD_DIR}/_sysconfigdata.py
-        COMMAND $<TARGET_FILE:python> -E -S -m sysconfig --generate-posix-vars
+        COMMAND ${PYTHON_WRAPPER_COMMAND} $<TARGET_FILE:python> -E -S -m sysconfig --generate-posix-vars
         COMMAND ${CMAKE_COMMAND}
           -DBIN_BUILD_DIR:PATH=${BIN_BUILD_DIR}
           -DPYTHON_BINARY_DIR:PATH=${CMAKE_BINARY_DIR}