cvs is using an old version of gnulib's openat.c unit which contains an openat() replacement. Unfortunately that version of openat.c contains bad code when trying to access mode_t through vararg; it does only produce a warning, but if the execution reach that code, the program aborts (as told by the warning itself). The attached patch replaces the bad code with the updated one in recent openat.c unit files (the unit is way different but this patch should be enough). Current CVS version of cvs already has openat.c updated from gnulib. Thanks, Diego
Created attachment 80835 [details, diff] cvs-1.12.12-mode_t.patch
Fixed in cvs-1.12.12-r3.