One more try. Use full path by default, and relative on broken compilers.

Tests/IncludeDirectories/CMakeLists.txt

@@ -14,10 +14,34 @@ file(WRITE ${CMAKE_BINARY_DIR}/TarProp/TarProp.h
 "//TarProp.h
 ")
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -IFlags")
+# default to testing with full path
+# some compilers can not handle the escape for directories
+# with spaces in them.
+set(USE_FULLPATH TRUE)
+if(WATCOM OR MSVC60)
+  set(USE_FULLPATH FALSE)
+endif()
+if(USE_FULLPATH)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} \"-I${CMAKE_BINARY_DIR}/Flags\"")
+else()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -IFlags")
+endif()
+
 include_directories(${CMAKE_BINARY_DIR}/IncDir)
-set_source_files_properties(main.cpp PROPERTIES COMPILE_FLAGS
-  "-ISrcProp")
+if(USE_FULLPATH)
+  set_source_files_properties(main.cpp PROPERTIES COMPILE_FLAGS
+    "\"-I${CMAKE_BINARY_DIR}/SrcProp\"")
+else()
+  set_source_files_properties(main.cpp PROPERTIES COMPILE_FLAGS
+    "-ISrcProp")
+endif()
+
 add_executable(IncludeDirectories main.cpp)
-set_target_properties(IncludeDirectories
-  PROPERTIES COMPILE_FLAGS "-ITarProp")
+
+if(USE_FULLPATH)
+  set_target_properties(IncludeDirectories
+    PROPERTIES COMPILE_FLAGS "\"-I${CMAKE_BINARY_DIR}/TarProp\"")
+else()
+  set_target_properties(IncludeDirectories
+    PROPERTIES COMPILE_FLAGS "-ITarProp")
+endif()