[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/xmountains_2.11-3_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

[...]
      |                                 ^~~~~~~~~~~
      |                                 |
      |                                 void (*)(void)
In file included from xmountains.c:5:
/usr/include/signal.h:88:57: note: expected ‘__sighandler_t’ {aka ‘void (*)(int)’} but argument is of type ‘void (*)(void)’
   88 | extern __sighandler_t signal (int __sig, __sighandler_t __handler)
      |                                          ~~~~~~~~~~~~~~~^~~~~~~~~
xmountains.c:98:6: note: ‘finish_prog’ declared here
   98 | void finish_prog();
      |      ^~~~~~~~~~~
/usr/include/signal.h:72:16: note: ‘__sighandler_t’ declared here
   72 | typedef void (*__sighandler_t) (int);
      |                ^~~~~~~~~~~~~~
xmountains.c:438:34: error: passing argument 2 of ‘signal’ from incompatible pointer type [-Wincompatible-pointer-types]
  438 |   if( SIG_ERR == signal(SIGTERM, finish_prog ))
      |                                  ^~~~~~~~~~~
      |                                  |
      |                                  void (*)(void)
/usr/include/signal.h:88:57: note: expected ‘__sighandler_t’ {aka ‘void (*)(int)’} but argument is of type ‘void (*)(void)’
   88 | extern __sighandler_t signal (int __sig, __sighandler_t __handler)
      |                                          ~~~~~~~~~~~~~~~^~~~~~~~~
xmountains.c:98:6: note: ‘finish_prog’ declared here
   98 | void finish_prog();
      |      ^~~~~~~~~~~
/usr/include/signal.h:72:16: note: ‘__sighandler_t’ declared here
   72 | typedef void (*__sighandler_t) (int);
      |                ^~~~~~~~~~~~~~
xmountains.c:443:33: error: passing argument 2 of ‘signal’ from incompatible pointer type [-Wincompatible-pointer-types]
  443 |   if( SIG_ERR == signal(SIGHUP, finish_prog ))
      |                                 ^~~~~~~~~~~
      |                                 |
      |                                 void (*)(void)
/usr/include/signal.h:88:57: note: expected ‘__sighandler_t’ {aka ‘void (*)(int)’} but argument is of type ‘void (*)(void)’
   88 | extern __sighandler_t signal (int __sig, __sighandler_t __handler)
      |                                          ~~~~~~~~~~~~~~~^~~~~~~~~
xmountains.c:98:6: note: ‘finish_prog’ declared here
   98 | void finish_prog();
      |      ^~~~~~~~~~~
/usr/include/signal.h:72:16: note: ‘__sighandler_t’ declared here
   72 | typedef void (*__sighandler_t) (int);
      |                ^~~~~~~~~~~~~~
xmountains.c:448:34: error: passing argument 2 of ‘signal’ from incompatible pointer type [-Wincompatible-pointer-types]
  448 |   if( SIG_ERR == signal(SIGQUIT, finish_prog ))
      |                                  ^~~~~~~~~~~
      |                                  |
      |                                  void (*)(void)
/usr/include/signal.h:88:57: note: expected ‘__sighandler_t’ {aka ‘void (*)(int)’} but argument is of type ‘void (*)(void)’
   88 | extern __sighandler_t signal (int __sig, __sighandler_t __handler)
      |                                          ~~~~~~~~~~~~~~~^~~~~~~~~
xmountains.c:98:6: note: ‘finish_prog’ declared here
   98 | void finish_prog();
      |      ^~~~~~~~~~~
/usr/include/signal.h:72:16: note: ‘__sighandler_t’ declared here
   72 | typedef void (*__sighandler_t) (int);
      |                ^~~~~~~~~~~~~~
make[1]: *** [<builtin>: calcalt.o] Error 1
make[1]: *** [<builtin>: xmountains.o] Error 1
make[1]: *** [<builtin>: artist.o] Error 1
random.c: In function ‘rstart’:
random.c:59:6: warning: old-style function definition [-Wold-style-definition]
   59 | void rstart(i,j,k,l)
      |      ^~~~~~
random.c: In function ‘seed_uni’:
random.c:102:6: warning: old-style function definition [-Wold-style-definition]
  102 | void seed_uni(ijkl)
      |      ^~~~~~~~
make[1]: Leaving directory '/build/reproducible-path/xmountains-2.11'
dh_auto_build: error: make -j8 "INSTALL=install --strip-program=true" returned exit code 2
make: *** [debian/rules:8: binary] Error 25
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2