I'm experimentally rebuilding rawhide with the not-yet-released GCC 15 to see if anything breaks, and to help write the porting guide.  See https://fedoraproject.org/wiki/User:Dmalcolm/gcc-15

My test build with GCC 15 failed:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed/build/8476048/

whereas my test build with GCC 14 succeeded:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed.checker/build/8477600/

Looking at the failure logs e.g.
https://download.copr.fedorainfracloud.org/results/dmalcolm/gcc-15-smoketest-3.failed/fedora-rawhide-x86_64/08476048-R-stringdist/builder-live.log.gz

I see:

stringdist.c: In function 'close_stringdist':
stringdist.c:110:5: error: too many arguments to function 'free_dictionary'
  110 |     free_dictionary(S->dict);
      |     ^~~~~~~~~~~~~~~
In file included from stringdist.c:24:
dist.h:11:6: note: declared here
   11 | void free_dictionary();
      |      ^~~~~~~~~~~~~~~
stringdist.c:113:5: error: too many arguments to function 'free_qtree'
  113 |     free_qtree(S->tree);
      |     ^~~~~~~~~~
dist.h:19:6: note: declared here
   19 | void free_qtree();
      |      ^~~~~~~~~~
stringdist.c: In function 'reset_stringdist':
stringdist.c:120:7: error: too many arguments to function 'free_qtree'
  120 |       free_qtree(S->tree);
      |       ^~~~~~~~~~
dist.h:19:6: note: declared here
   19 | void free_qtree();
      |      ^~~~~~~~~~

This is probably due to GCC 15 now defaulting to -std=gnu23, whereas GCC 14 defaulted to -std=gnu17, and C23 is stricter about function prototypes than C17.  It's probably fixable by fixing the function prototypes (or by manually adding -std=gnu17 to the C build flags)


Reproducible: Always