Temporary header file '/tmp/X4cFspgw5S/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

  // add includes
  #include "/usr/include/dpkg/ar.h"
  #include "/usr/include/dpkg/arch.h"
  #include "/usr/include/dpkg/atomic-file.h"
  #include "/usr/include/dpkg/buffer.h"
  #include "/usr/include/dpkg/c-ctype.h"
  #include "/usr/include/dpkg/color.h"
  #include "/usr/include/dpkg/command.h"
  #include "/usr/include/dpkg/compress.h"
  #include "/usr/include/dpkg/db-ctrl.h"
  #include "/usr/include/dpkg/db-fsys.h"
  #include "/usr/include/dpkg/deb-version.h"
  #include "/usr/include/dpkg/debug.h"
  #include "/usr/include/dpkg/dir.h"
  #include "/usr/include/dpkg/dpkg-db.h"
  #include "/usr/include/dpkg/dpkg.h"
  #include "/usr/include/dpkg/ehandle.h"
  #include "/usr/include/dpkg/error.h"
  #include "/usr/include/dpkg/fdio.h"
  #include "/usr/include/dpkg/file.h"
  #include "/usr/include/dpkg/fsys.h"
  #include "/usr/include/dpkg/glob.h"
  #include "/usr/include/dpkg/macros.h"
  #include "/usr/include/dpkg/meminfo.h"
  #include "/usr/include/dpkg/namevalue.h"
  #include "/usr/include/dpkg/options.h"
  #include "/usr/include/dpkg/pager.h"
  #include "/usr/include/dpkg/parsedump.h"
  #include "/usr/include/dpkg/path.h"
  #include "/usr/include/dpkg/pkg-array.h"
  #include "/usr/include/dpkg/pkg-files.h"
  #include "/usr/include/dpkg/pkg-format.h"
  #include "/usr/include/dpkg/pkg-list.h"
  #include "/usr/include/dpkg/pkg-queue.h"
  #include "/usr/include/dpkg/pkg-show.h"
  #include "/usr/include/dpkg/pkg-spec.h"
  #include "/usr/include/dpkg/pkg.h"
  #include "/usr/include/dpkg/progname.h"
  #include "/usr/include/dpkg/program.h"
  #include "/usr/include/dpkg/progress.h"
  #include "/usr/include/dpkg/report.h"
  #include "/usr/include/dpkg/string.h"
  #include "/usr/include/dpkg/subproc.h"
  #include "/usr/include/dpkg/tarfn.h"
  #include "/usr/include/dpkg/treewalk.h"
  #include "/usr/include/dpkg/trigdeferred.h"
  #include "/usr/include/dpkg/triglib.h"
  #include "/usr/include/dpkg/varbuf.h"
  #include "/usr/include/dpkg/version.h"

  // add classes
  _G_fpos64_t* tmp_add_class_0;
  _G_fpos_t* tmp_add_class_1;
  _IO_cookie_io_functions_t* tmp_add_class_2;
  arbitraryfield* tmp_add_class_3;
  archivedetails* tmp_add_class_4;
  atomic_file* tmp_add_class_5;
  buffer_data* tmp_add_class_6;
  cmdinfo* tmp_add_class_7;
  command* tmp_add_class_8;
  compress_params* tmp_add_class_9;
  conffile* tmp_add_class_10;
  deb_version* tmp_add_class_11;
  dependency* tmp_add_class_12;
  deppossi* tmp_add_class_13;
  dpkg_ar* tmp_add_class_14;
  dpkg_ar_hdr* tmp_add_class_15;
  dpkg_ar_member* tmp_add_class_16;
  dpkg_arch* tmp_add_class_17;
  dpkg_error* tmp_add_class_18;
  dpkg_version* tmp_add_class_19;
  field_state* tmp_add_class_20;
  fieldinfo* tmp_add_class_21;
  file_ondisk_id* tmp_add_class_22;
  file_stat* tmp_add_class_23;
  fsys_diversion* tmp_add_class_24;
  fsys_hash_rev_iter* tmp_add_class_25;
  fsys_namenode* tmp_add_class_26;
  fsys_namenode_list* tmp_add_class_27;
  fsys_namenode_queue* tmp_add_class_28;
  glob_node* tmp_add_class_29;
  namevalue* tmp_add_class_30;
  parsedb_state* tmp_add_class_31;
  pkg_array* tmp_add_class_32;
  pkg_list* tmp_add_class_33;
  pkg_queue* tmp_add_class_34;
  pkg_spec* tmp_add_class_35;
  pkgbin* tmp_add_class_36;
  pkginfo* tmp_add_class_37;
  pkgset* tmp_add_class_38;
  progress* tmp_add_class_39;
  statx_timestamp* tmp_add_class_40;
  str_crop_info* tmp_add_class_41;
  tar_archive* tmp_add_class_42;
  tar_entry* tmp_add_class_43;
  tar_operations* tmp_add_class_44;
  treewalk_funcs* tmp_add_class_45;
  trig_hooks* tmp_add_class_46;
  trigaw* tmp_add_class_47;
  trigdefmeths* tmp_add_class_48;
  trigfileint* tmp_add_class_49;
  trigpend* tmp_add_class_50;
  varbuf* tmp_add_class_51;
  varbuf_state* tmp_add_class_52;

The GCC parameters:
  gcc -fdump-lang-raw -fkeep-inline-functions -c -x c++ -fpermissive -w "/tmp/X4cFspgw5S/dump1.h"

In file included from /usr/include/dpkg/ar.h:29,
                 from /tmp/X4cFspgw5S/dump1.h:11:
/usr/include/dpkg/macros.h:31:2: error: #error "The libdpkg API is to be considered volatile, please read 'README.api'."
   31 | #error "The libdpkg API is to be considered volatile, please read 'README.api'."
      |  ^~~~~