Temporary header file '/tmp/Px72b6_DqQ/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/argagg/argagg.hpp"
  #include "/usr/include/argagg/convert/csv.hpp"
  #include "/usr/include/argagg/convert/opencv.hpp"

  // add namespaces
  namespace argagg{typedef int tmp_add_type_1;}
  argagg::tmp_add_type_1 tmp_add_func_1(){return 0;};
  namespace argagg{namespace convert{typedef int tmp_add_type_2;}}
  argagg::convert::tmp_add_type_2 tmp_add_func_2(){return 0;};

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/Px72b6_DqQ/dump1.h"

In file included from /tmp/Px72b6_DqQ/dump1.h:14:
/usr/include/argagg/convert/opencv.hpp:36:10: fatal error: opencv2/opencv.hpp: No such file or directory
   36 | #include <opencv2/opencv.hpp>
      |          ^~~~~~~~~~~~~~~~~~~~
compilation terminated.