https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93469
--- Comment #13 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Sergey Fedorov from comment #12) > (In reply to Jonathan Wakely from comment #10) > > The same error happens even without the macro in question being passed, at > least explicitly. Getting it with gcc 14.2.0 and ICU 76.1 (on x86_64, but > not on powerpc). 10.15 (Catalina) should have aligned_alloc() whereas 10.5 does not. Look at what the (libstdc++-v3) build tree values for _GLIBCXX_HAVE_ALIGNED_ALLOC and HAVE_ALIGNED_ALLOC are. Then take a look at what the project is adding - it is quite possible that some other macro (e.g. *POSIX*) is preventing the declarations from being visible.
