diff -ur extra-cmake-modules-1.6.0/kde-modules/KDEInstallDirs.cmake extra-cmake-modules-1.6.0-KDEInstallDirs-no-unset/kde-modules/KDEInstallDirs.cmake
--- extra-cmake-modules-1.6.0/kde-modules/KDEInstallDirs.cmake	2014-12-28 18:34:30.000000000 +0100
+++ extra-cmake-modules-1.6.0-KDEInstallDirs-no-unset/kde-modules/KDEInstallDirs.cmake	2015-01-11 03:58:29.000000000 +0100
@@ -290,10 +290,6 @@
             CACHE PATH
                   "${docstring} (${_docpath})"
                   FORCE)
-        unset(${_oldstylename} CACHE)
-        if(_cmakename AND ${_cmakename})
-            unset(${_cmakename} CACHE)
-        endif()
     elseif(${_cmakename})
         if(_cmakename_is_deprecated AND NOT CMAKE_VERSION VERSION_LESS 3.0.0)
             message(DEPRECATION "${_cmakename} is deprecated, use KDE_INSTALL_${varname} instead.")
@@ -304,7 +300,6 @@
             CACHE PATH
                   "${docstring} (${_docpath})"
                   FORCE)
-        unset(${_cmakename} CACHE)
     elseif(NOT KDE_INSTALL_${varname})
         set(KDE_INSTALL_${varname} ""
             CACHE PATH "${docstring} (${_docpath})")