[This bug is NOT targeted to the upcoming trixie release]

Please keep this issue open in the bug tracker for the package it
was filed for.  If a fix in another package is required, please
file a bug for the other package (or clone), and add a block in this
package. Please keep the issue open until the package can be built in
a follow-up test rebuild.

The package fails to build in a test rebuild on at least amd64 with
gcc-15/g++-15, but succeeds to build with gcc-14/g++-14. The
severity of this report will be raised before the forky release.

The full build log can be found at:
http://qa-logs.debian.net/2025/02/16/amd64exp/macopix_3.4.0+dfsg.1-3_unstable_gccexp.log.gz
The last lines of the build log are at the end of this report.

To build with GCC 15, either set CC=gcc-15 CXX=g++-15 explicitly,
or install the gcc, g++, gfortran, ... packages from experimental.

  apt-get -t=experimental install g++

GCC 15 now defaults to the C23/C++23 standards, exposing many FTBFS.
Other Common build failures are new warnings resulting in build failures
with -Werror turned on, or new/dropped symbols in Debian symbols files.
For other C/C++ related build failures see the porting guide at
http://gcc.gnu.org/gcc-15/porting_to.html

[...]
      |             ^~~~~~~~~~~~~~
gui.c:358:13: note: previous declaration of ‘cattree_up_tgt’ with type ‘void(void)’
  358 | static void cattree_up_tgt();
      |             ^~~~~~~~~~~~~~
gui.c:13754:13: error: conflicting types for ‘cattree_down_tgt’; have ‘void(GtkWidget *, void *)’ {aka ‘void(struct _GtkWidget *, void *)’}
13754 | static void cattree_down_tgt (GtkWidget *widget, gpointer gdata)
      |             ^~~~~~~~~~~~~~~~
gui.c:359:13: note: previous declaration of ‘cattree_down_tgt’ with type ‘void(void)’
  359 | static void cattree_down_tgt();
      |             ^~~~~~~~~~~~~~~~
gui.c:283:13: warning: ‘create_save_mascot_dialog’ used but never defined
  283 | static void create_save_mascot_dialog();
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~
gui.c:332:13: warning: ‘imgtree_add_columns’ used but never defined
  332 | static void imgtree_add_columns();
      |             ^~~~~~~~~~~~~~~~~~~
gui.c:333:22: warning: ‘imgtree_create_items_model’ used but never defined
  333 | static GtkTreeModel *imgtree_create_items_model ();
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
gui.c:335:13: warning: ‘focus_imgtree_item’ used but never defined
  335 | static void focus_imgtree_item();
      |             ^~~~~~~~~~~~~~~~~~
gui.c:336:13: warning: ‘act_imgtree_item’ used but never defined
  336 | static void act_imgtree_item();
      |             ^~~~~~~~~~~~~~~~
gui.c:341:13: warning: ‘ptntree_add_columns’ used but never defined
  341 | static void ptntree_add_columns();
      |             ^~~~~~~~~~~~~~~~~~~
gui.c:342:22: warning: ‘ptntree_create_items_model’ used but never defined
  342 | static GtkTreeModel *ptntree_create_items_model ();
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
gui.c:344:13: warning: ‘focus_ptntree_item’ used but never defined
  344 | static void focus_ptntree_item();
      |             ^~~~~~~~~~~~~~~~~~
gui.c:346:13: warning: ‘ptntree_cell_edited’ used but never defined
  346 | static void ptntree_cell_edited ();
      |             ^~~~~~~~~~~~~~~~~~~
gui.c:351:13: warning: ‘cattree_add_columns’ used but never defined
  351 | static void cattree_add_columns();
      |             ^~~~~~~~~~~~~~~~~~~
gui.c:352:22: warning: ‘cattree_create_items_model’ used but never defined
  352 | static GtkTreeModel *cattree_create_items_model ();
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
gui.c:354:13: warning: ‘focus_cattree_item’ used but never defined
  354 | static void focus_cattree_item();
      |             ^~~~~~~~~~~~~~~~~~
gui.c:356:13: warning: ‘act_cattree_item’ used but never defined
  356 | static void act_cattree_item();
      |             ^~~~~~~~~~~~~~~~
gui.c:358:13: warning: ‘cattree_up_tgt’ used but never defined
  358 | static void cattree_up_tgt();
      |             ^~~~~~~~~~~~~~
gui.c:359:13: warning: ‘cattree_down_tgt’ used but never defined
  359 | static void cattree_down_tgt();
      |             ^~~~~~~~~~~~~~~~
make[6]: *** [Makefile:619: gui.o] Error 1
make[6]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1/src'
make[5]: *** [Makefile:648: all-recursive] Error 1
make[5]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1/src'
make[4]: *** [Makefile:484: all] Error 2
make[4]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1/src'
make[3]: *** [Makefile:583: all-recursive] Error 1
make[3]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1'
make[2]: *** [Makefile:470: all] Error 2
make[2]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1'
dh_auto_build: error: make -j8 returned exit code 2
make[1]: *** [debian/rules:14: override_dh_auto_build] Error 25
make[1]: Leaving directory '/build/reproducible-path/macopix-3.4.0+dfsg.1'
make: *** [debian/rules:5: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2