Temporary header file '/tmp/jH9FvWBW5C/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/rgpio.h" The GCC parameters: gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/jH9FvWBW5C/dump1.h" In file included from /tmp/jH9FvWBW5C/dump1.h:12: /usr/include/rgpio.h:34:10: fatal error: lgpio.h: No such file or directory 34 | #include "lgpio.h" | ^~~~~~~~~ compilation terminated.