https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80677
--- Comment #2 from Helmut Grohne <helmut at subdivi dot de> --- (In reply to jos...@codesourcery.com from comment #1) > Well, if headers move then configure (and related) tests that look at them > will need updating. See how gcc/configure.ac looks in $target_header_dir > to identify the glibc version and various other configuration, for > example. As far as I understand it, gcc's build system takes care to consult $(build_tooldir)/sys-include. Debian's packaging of gcc takes care to populate it reasonably. I have performed a fair number of builds of gcc with glibc's headers moved now and cannot confirm the projected behavior. At present, it looks like fixing LIMITS_H_TEST is the remaining piece to the puzzle.