Temporary header file '/tmp/cBUDWVIEfe/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/lammps/angle.h"
  #include "/usr/include/lammps/atom.h"
  #include "/usr/include/lammps/bond.h"
  #include "/usr/include/lammps/citeme.h"
  #include "/usr/include/lammps/comm.h"
  #include "/usr/include/lammps/compute.h"
  #include "/usr/include/lammps/dihedral.h"
  #include "/usr/include/lammps/domain.h"
  #include "/usr/include/lammps/error.h"
  #include "/usr/include/lammps/fix.h"
  #include "/usr/include/lammps/force.h"
  #include "/usr/include/lammps/group.h"
  #include "/usr/include/lammps/improper.h"
  #include "/usr/include/lammps/info.h"
  #include "/usr/include/lammps/input.h"
  #include "/usr/include/lammps/kspace.h"
  #include "/usr/include/lammps/lammps.h"
  #include "/usr/include/lammps/lattice.h"
  #include "/usr/include/lammps/library.h"
  #include "/usr/include/lammps/lmppython.h"
  #include "/usr/include/lammps/lmptype.h"
  #include "/usr/include/lammps/memory.h"
  #include "/usr/include/lammps/modify.h"
  #include "/usr/include/lammps/neigh_list.h"
  #include "/usr/include/lammps/neighbor.h"
  #include "/usr/include/lammps/output.h"
  #include "/usr/include/lammps/pair.h"
  #include "/usr/include/lammps/pointers.h"
  #include "/usr/include/lammps/region.h"
  #include "/usr/include/lammps/timer.h"
  #include "/usr/include/lammps/universe.h"
  #include "/usr/include/lammps/update.h"
  #include "/usr/include/lammps/utils.h"
  #include "/usr/include/lammps/variable.h"

  // add namespaces
  namespace LAMMPS_NS{typedef int tmp_add_type_1;}
  LAMMPS_NS::tmp_add_type_1 tmp_add_func_1(){return 0;};

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

In file included from /usr/include/lammps/angle.h:17,
                 from /tmp/cBUDWVIEfe/dump1.h:12:
/usr/include/lammps/pointers.h:26:10: fatal error: mpi.h: No such file or directory
   26 | #include <mpi.h>        // IWYU pragma: export
      |          ^~~~~~~
compilation terminated.