$ git clone -n https://src.fedoraproject.org/rpms/mozjs128.git /var/lib/mock/f42-build-3346777-45002/root/chroot_tmpdir/scmroot/mozjs128
Cloning into '/var/lib/mock/f42-build-3346777-45002/root/chroot_tmpdir/scmroot/mozjs128'...
$ git fetch origin f8a4ac1ecfb3263e647d8bff695a256713aa4f1e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mozjs128
 * [new ref]         f8a4ac1ecfb3263e647d8bff695a256713aa4f1e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f8a4ac1 Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild