GNAT is required to build GNAT. sys-devel/gcc ebuild does not pull in a bootstrap and therefore it will not build. Reproducible: Always Steps to Reproduce: printf -- '-ada\n' >> /etc/portage/use.mask USE=ada emerge -a1v gcc Actual Results: ... checking for objdir... .libs checking for the correct version of gmp.h... yes checking for the correct version of mpfr.h... yes checking for the correct version of mpc.h... yes checking for the correct version of the gmp/mpfr/mpc libraries... yes configure: error: GNAT is required to build ada * ERROR: sys-devel/gcc-10.2.0-r5::gentoo failed (configure phase): * failed to run configure ... Expected Results: Working GNAT
and I showed how it should be done but you wouldn't accept it https://github.com/Lucretia/ada-overlay/blob/master/eclass/toolchain.eclass#L404
*** This bug has been marked as a duplicate of bug 592060 ***