Fix GNUInstallDirs includedir detection

CMake uses `INCLUDEDIR` instead of `INCDIR`.

diff --git a/cmake/detect-install-dirs.cmake b/cmake/detect-install-dirs.cmake
index 421495479c690ae3f5560a329177ee64289b6815..ddf1adb8c2caa839303b032ce851aac2642e227c 100644 (file)
--- a/cmake/detect-install-dirs.cmake
+++ b/cmake/detect-install-dirs.cmake
@@ -33,9 +33,9 @@ if (DEFINED INC_INSTALL_DIR)
     set(INC_INSTALL_DIR "${INC_INSTALL_DIR}" CACHE PATH "Installation directory for headers" FORCE)
 elseif (DEFINED INSTALL_INC_DIR)
     set(INC_INSTALL_DIR "${INSTALL_INC_DIR}" CACHE PATH "Installation directory for headers" FORCE)
-elseif (DEFINED CMAKE_INSTALL_FULL_INCDIR)
+elseif (DEFINED CMAKE_INSTALL_FULL_INCLUDEDIR)
     set(INC_INSTALL_DIR "${CMAKE_INSTALL_FULL_INCLUDEDIR}" CACHE PATH "Installation directory for headers" FORCE)
-elseif (DEFINED CMAKE_INSTALL_INCDIR)
+elseif (DEFINED CMAKE_INSTALL_INCLUDEDIR)
     set(INC_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}" CACHE PATH "Installation directory for headers" FORCE)
 else()
     set(INC_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/include" CACHE PATH "Installation directory for headers")