https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106097
--- Comment #3 from Xi Ruoyao <xry111 at mengyan1223 dot wang> --- (In reply to Andrew Pinski from comment #2) > by using the --with-build-config=bootstrap-ubsan option at configure time or > BUILD_CONFIG variable to build time. > > See https://gcc.gnu.org/install/build.html The problem is -fsanitize=undefined does not work on LoongArch for now. But it can be reproduced by building a cross compile on x86_64: /path/to/gcc/configure --target=loongarch64-linux-gnu make {C,CXX}FLAGS="-O2 -g -fsanitize=undefined" all-gcc