%rename cpp_options old_cpp_options
*cpp_options:
--nostdinc -isystem $incdir %(old_cpp_options)
+-nostdinc -isystem $incdir -isystem include%s %(old_cpp_options)
*cc1:
-%(cc1_cpu) -nostdinc -isystem $incdir
+%(cc1_cpu) -nostdinc -isystem $incdir -isystem include%s
*link_libgcc:
-L$libdir -L .%s