Paul Eggert wrote: > as you mentioned we should use the > --std=gnu23 option anyway. I installed the attached to do that.
Thanks. Both patches work fine. Now the gcc option is found and activated: checking for /gnu-inst-gcc/15-20241113/bin/gcc -ftrapv option to enable C23 features... -std=gnu23 IMO they are ready to sync back into Autoconf's c.m4. In the config.log I still see a warning: conftest.c:74:21: warning: 'null_pointer' defined but not used [-Wunused-const-variable=] 74 | constexpr nullptr_t null_pointer = nullptr; | ^~~~~~~~~~~~ Maybe you want to silence that as well, just in case someone is using -Werror? Bruno