Temporary header file '/tmp/5U_8axvhpU/dump1.h' with the following content will be compiled to create GCC translation unit dump: // add defines #define __STDC_VERSION__ 201710L #define _GXX_NULLPTR_T #define CLUTTER_ENABLE_COMPOSITOR_API 1 #define _REGEX_NELTS(n) #define _Atomic #define PACKED #define getaddrinfo_a(a,b,c,d) // add includes #include "/usr/include/signon-plugins/sasldata.h" The GCC parameters: gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/5U_8axvhpU/dump1.h" In file included from /tmp/5U_8axvhpU/dump1.h:12: /usr/include/signon-plugins/sasldata.h:31:10: fatal error: SignOn/SessionData: No such file or directory 31 | #include | ^~~~~~~~~~~~~~~~~~~~ compilation terminated.