Hello I build gcc version 12.0.0 20210603 (experimental) locally, then tried REL_13_STABLE with same CFLAGS as serinus ./configure --prefix=/home/melkij/tmp/pgdev/inst CFLAGS="-O3 -ggdb -g3 -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare -Wno-missing-field-initializers" --enable-tap-tests --enable-cassert --enable-debug check-world passed.
regards, Sergei