Temporary header file '/tmp/5EIwVz1FK2/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/IsoSpec++/allocator.h"
  #include "/usr/include/IsoSpec++/btrd.h"
  #include "/usr/include/IsoSpec++/conf.h"
  #include "/usr/include/IsoSpec++/cwrapper.h"
  #include "/usr/include/IsoSpec++/dirtyAllocator.h"
  #include "/usr/include/IsoSpec++/element_tables.h"
  #include "/usr/include/IsoSpec++/fasta.h"
  #include "/usr/include/IsoSpec++/fixedEnvelopes.h"
  #include "/usr/include/IsoSpec++/isoMath.h"
  #include "/usr/include/IsoSpec++/isoSpec++.h"
  #include "/usr/include/IsoSpec++/marginalTrek++.h"
  #include "/usr/include/IsoSpec++/misc.h"
  #include "/usr/include/IsoSpec++/mman.h"
  #include "/usr/include/IsoSpec++/operators.h"
  #include "/usr/include/IsoSpec++/platform.h"
  #include "/usr/include/IsoSpec++/platform_incl.h"
  #include "/usr/include/IsoSpec++/pod_vector.h"
  #include "/usr/include/IsoSpec++/summator.h"

  // add namespaces
  namespace IsoSpec{typedef int tmp_add_type_1;}
  IsoSpec::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/5EIwVz1FK2/dump1.h"

In file included from /tmp/5EIwVz1FK2/dump1.h:24:
/usr/include/IsoSpec++/mman.h:26:10: fatal error: _mingw.h: No such file or directory
   26 | #include <_mingw.h>
      |          ^~~~~~~~~~
compilation terminated.