https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113749
--- Comment #1 from Gaius Mulley <gaius at gcc dot gnu.org> --- Thanks for the bug report - I suspect this requires the same bug fix as PR 112920 - gm2 hangs in the type resolver. Although the hang in this PR is in the bootstrap tool - they both use the same type resolving algorithm.
