Bug#1097450: nethack: ftbfs with GCC-15

[Matthias Klose]

Package: src:nethack
Version: 3.6.7-1
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/nethack_3.6.7-1_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

[...]
makedefs.c:1822:1: warning: old-style function definition [-Wold-style-definition]
 1822 | opt_out_words(str, length_p)
      | ^~~~~~~~~~~~~
makedefs.c: In function ‘d_filter’:
makedefs.c:1926:1: warning: old-style function definition [-Wold-style-definition]
 1926 | d_filter(line)
      | ^~~~~~~~
makedefs.c: In function ‘h_filter’:
makedefs.c:2072:1: warning: old-style function definition [-Wold-style-definition]
 2072 | h_filter(line)
      | ^~~~~~~~
makedefs.c: In function ‘qt_comment’:
makedefs.c:2435:1: warning: old-style function definition [-Wold-style-definition]
 2435 | qt_comment(s)
      | ^~~~~~~~~~
makedefs.c: In function ‘qt_control’:
makedefs.c:2444:1: warning: old-style function definition [-Wold-style-definition]
 2444 | qt_control(s)
      | ^~~~~~~~~~
makedefs.c: In function ‘get_hdr’:
makedefs.c:2451:1: warning: old-style function definition [-Wold-style-definition]
 2451 | get_hdr(code)
      | ^~~~~~~
makedefs.c: In function ‘new_id’:
makedefs.c:2464:1: warning: old-style function definition [-Wold-style-definition]
 2464 | new_id(code)
      | ^~~~~~
makedefs.c: In function ‘known_msg’:
makedefs.c:2479:1: warning: old-style function definition [-Wold-style-definition]
 2479 | known_msg(num, id)
      | ^~~~~~~~~
makedefs.c: In function ‘new_msg’:
makedefs.c:2492:1: warning: old-style function definition [-Wold-style-definition]
 2492 | new_msg(s, num, id)
      | ^~~~~~~
makedefs.c: In function ‘valid_qt_summary’:
makedefs.c:2513:1: warning: old-style function definition [-Wold-style-definition]
 2513 | valid_qt_summary(s, parsing)
      | ^~~~~~~~~~~~~~~~
makedefs.c: In function ‘do_qt_control’:
makedefs.c:2563:1: warning: old-style function definition [-Wold-style-definition]
 2563 | do_qt_control(s)
      | ^~~~~~~~~~~~~
makedefs.c: In function ‘do_qt_text’:
makedefs.c:2611:1: warning: old-style function definition [-Wold-style-definition]
 2611 | do_qt_text(s)
      | ^~~~~~~~~~
makedefs.c: In function ‘limit’:
makedefs.c:2769:14: warning: old-style function definition [-Wold-style-definition]
 2769 | static char *limit(name, pref) /* limit a name to 30 characters length */
      |              ^~~~~
makedefs.c: In function ‘fgetline’:
makedefs.c:2916:1: warning: old-style function definition [-Wold-style-definition]
 2916 | fgetline(fd)
      | ^~~~~~~~
makedefs.c: In function ‘tmpdup’:
makedefs.c:2940:1: warning: old-style function definition [-Wold-style-definition]
 2940 | tmpdup(str)
      | ^~~~~~
makedefs.c: In function ‘eos’:
makedefs.c:2952:1: warning: old-style function definition [-Wold-style-definition]
 2952 | eos(str)
      | ^~~
make[2]: *** [<builtin>: makedefs.o] Error 1
make[2]: *** [Makefile:478: ../src/monst.o] Error 1
make[2]: Leaving directory '/build/reproducible-path/nethack-3.6.7/util'
make[1]: *** [debian/rules:21: override_dh_auto_build] Error 2
make[1]: Leaving directory '/build/reproducible-path/nethack-3.6.7'
make: *** [debian/rules:86: build] Error 2
dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2