[Debian-on-mobile-maintainers] Bug#1097380: megapixels: ftbfs with GCC-15

[Matthias Klose]

Package: src:megapixels
Version: 1.8.3-1
Severity: important
Tags: sid forky
User: debian-gcc at lists.debian.org
Usertags: ftbfs-gcc-15

[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/megapixels_1.8.3-1_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

[...]
  622 |                 dialog = gtk_message_dialog_new(
      |                 ^~~~~~
In file included from /usr/include/gtk-4.0/gtk/gtk.h:192:
/usr/include/gtk-4.0/gtk/deprecated/gtkmessagedialog.h:81:12: note: declared here
   81 | GtkWidget* gtk_message_dialog_new      (GtkWindow      *parent,
      |            ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:630:17: warning: ‘gtk_dialog_add_buttons’ is deprecated [-Wdeprecated-declarations]
  630 |                 gtk_dialog_add_buttons(
      |                 ^~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/gtk-4.0/gtk/deprecated/gtkappchooserdialog.h:31,
                 from /usr/include/gtk-4.0/gtk/gtk.h:43:
/usr/include/gtk-4.0/gtk/deprecated/gtkdialog.h:148:12: note: declared here
  148 | void       gtk_dialog_add_buttons       (GtkDialog   *dialog,
      |            ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:633:17: warning: ‘gtk_message_dialog_new’ is deprecated [-Wdeprecated-declarations]
  633 |                 dialog = gtk_message_dialog_new(
      |                 ^~~~~~
/usr/include/gtk-4.0/gtk/deprecated/gtkmessagedialog.h:81:12: note: declared here
   81 | GtkWidget* gtk_message_dialog_new      (GtkWindow      *parent,
      |            ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:640:17: warning: ‘gtk_message_dialog_format_secondary_markup’ is deprecated [-Wdeprecated-declarations]
  640 |                 gtk_message_dialog_format_secondary_markup(
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/gtk-4.0/gtk/deprecated/gtkmessagedialog.h:106:12: note: declared here
  106 | void       gtk_message_dialog_format_secondary_markup (GtkMessageDialog *message_dialog,
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/main.c:643:9: warning: ‘gtk_dialog_add_buttons’ is deprecated [-Wdeprecated-declarations]
  643 |         gtk_dialog_add_buttons(GTK_DIALOG(dialog),
      |         ^~~~~~~~~~~~~~~~~~~~~~
/usr/include/gtk-4.0/gtk/deprecated/gtkdialog.h:148:12: note: declared here
  148 | void       gtk_dialog_add_buttons       (GtkDialog   *dialog,
      |            ^~~~~~~~~~~~~~~~~~~~~~
../src/main.c:653:9: warning: ‘gtk_widget_show’ is deprecated: Use 'gtk_widget_set_visible or gtk_window_present' instead [-Wdeprecated-declarations]
  653 |         gtk_widget_show(GTK_WIDGET(dialog));
      |         ^~~~~~~~~~~~~~~
/usr/include/gtk-4.0/gtk/gtkwidget.h:274:12: note: declared here
  274 | void       gtk_widget_show                (GtkWidget           *widget);
      |            ^~~~~~~~~~~~~~~
../src/main.c: In function ‘xevent_handler’:
../src/main.c:1089:9: warning: ‘gdk_x11_display_get_xdisplay’ is deprecated [-Wdeprecated-declarations]
 1089 |         Display *xdisplay = gdk_x11_display_get_xdisplay(display);
      |         ^~~~~~~
In file included from /usr/include/gtk-4.0/gdk/x11/gdkx.h:39,
                 from ../src/main.c:22:
/usr/include/gtk-4.0/gdk/x11/gdkx11display.h:60:15: note: declared here
   60 | Display *     gdk_x11_display_get_xdisplay     (GdkDisplay  *display);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/main.c: In function ‘activate’:
../src/main.c:1261:17: warning: ‘gdk_x11_display_get_xdisplay’ is deprecated [-Wdeprecated-declarations]
 1261 |                 Display *xdisplay = gdk_x11_display_get_xdisplay(display);
      |                 ^~~~~~~
/usr/include/gtk-4.0/gdk/x11/gdkx11display.h:60:15: note: declared here
   60 | Display *     gdk_x11_display_get_xdisplay     (GdkDisplay  *display);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/main.c:1263:25: warning: ‘gdk_x11_display_get_xscreen’ is deprecated [-Wdeprecated-declarations]
 1263 |                         XScreenNumberOfScreen(gdk_x11_display_get_xscreen(display));
      |                         ^~~~~~~~~~~~~~~~~~~~~
/usr/include/gtk-4.0/gdk/x11/gdkx11display.h:62:15: note: declared here
   62 | Screen *      gdk_x11_display_get_xscreen      (GdkDisplay  *display);
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/main.c:1296:9: warning: ‘gtk_widget_show’ is deprecated: Use 'gtk_widget_set_visible or gtk_window_present' instead [-Wdeprecated-declarations]
 1296 |         gtk_widget_show(window);
      |         ^~~~~~~~~~~~~~~
/usr/include/gtk-4.0/gtk/gtkwidget.h:274:12: note: declared here
  274 | void       gtk_widget_show                (GtkWidget           *widget);
      |            ^~~~~~~~~~~~~~~
ninja: build stopped: subcommand failed.
dh_auto_build: error: cd _build && LC_ALL=C.UTF-8 ninja -j8 -v returned exit code 1
make: *** [debian/rules:6: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2