File lmms-1.2.0-libdir.patch of Package lmms

diff -up lmms/cmake/modules/DetectMachine.cmake.orig lmms/cmake/modules/DetectMachine.cmake
--- lmms/cmake/modules/DetectMachine.cmake.orig	2018-08-06 08:43:43.000000000 +0200
+++ lmms/cmake/modules/DetectMachine.cmake	2018-10-30 17:32:32.385021508 +0100
@@ -42,6 +42,13 @@ ENDIF(IS_X86)
 
 IF(CMAKE_INSTALL_LIBDIR)
 	SET(LIB_DIR "${CMAKE_INSTALL_LIBDIR}")
+    # Make LIB_DIR relative
+    STRING(FIND "${LIB_DIR}" "${CMAKE_INSTALL_PREFIX}" PREFIX_IDX)
+    IF(PREFIX_IDX EQUAL 0)
+            STRING(LENGTH "${CMAKE_INSTALL_PREFIX}" PREFIX_LEN)
+            STRING(SUBSTRING "${LIB_DIR}" ${PREFIX_LEN} -1 LIB_DIR)
+            STRING(REGEX REPLACE "^[/\\]" "" LIB_DIR "${LIB_DIR}")
+    ENDIF()
 ELSE(CMAKE_INSTALL_LIBDIR)
 	SET(LIB_DIR lib)
 ENDIF(CMAKE_INSTALL_LIBDIR)