https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121149
--- Comment #8 from Jose E. Marchesi <jemarch at gcc dot gnu.org> --- The top-level configure.ac uses: ACX_NONCANONICAL_BUILD ACX_NONCANONICAL_HOST ACX_NONCANONICAL_TARGET whereas libgcc/configure.ac uses: AC_CANONICAL_HOST ACX_NONCANONICAL_HOST ACX_NONCANONICAL_TARGET