https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65253 - this has been open since 2015 - probably should have been prioritized given it finds real world bugs.

GCC is still the king of the hill though - the amount of support for various ISAs, new features like C++20 stuff - it's far from lagging clang in hugely significant ways. (GCC user since 2.95 on Solaris/SPARC!)