Do not redefine GZ_PYTHON_INSTALL_PATH if it is already defined (#393)

Signed-off-by: Silvio Traversaro <[email protected]>

CMakeLists.txt

@@ -108,16 +108,18 @@ endif()
 # Find Python
 find_package(Python3 REQUIRED COMPONENTS Interpreter)
 
-if(USE_SYSTEM_PATHS_FOR_PYTHON_INSTALLATION)
- if(USE_DIST_PACKAGES_FOR_PYTHON)
- string(REPLACE "site-packages" "dist-packages" GZ_PYTHON_INSTALL_PATH ${Python3_SITELIB})
+if(NOT GZ_PYTHON_INSTALL_PATH)
+ if(USE_SYSTEM_PATHS_FOR_PYTHON_INSTALLATION)
+ if(USE_DIST_PACKAGES_FOR_PYTHON)
+ string(REPLACE "site-packages" "dist-packages" GZ_PYTHON_INSTALL_PATH ${Python3_SITELIB})
+ else()
+ # Python3_SITELIB might use dist-packages in some platforms
+ string(REPLACE "dist-packages" "site-packages" GZ_PYTHON_INSTALL_PATH ${Python3_SITELIB})
+ endif()
  else()
- # Python3_SITELIB might use dist-packages in some platforms
- string(REPLACE "dist-packages" "site-packages" GZ_PYTHON_INSTALL_PATH ${Python3_SITELIB})
+ # If not a system installation, respect local paths
+ set(GZ_PYTHON_INSTALL_PATH ${GZ_LIB_INSTALL_DIR}/python)
  endif()
-else()
- # If not a system installation, respect local paths
- set(GZ_PYTHON_INSTALL_PATH ${GZ_LIB_INSTALL_DIR}/python)
 endif()
 #============================================================================
 # Configure the build