$ git clone -n https://src.fedoraproject.org/rpms/rubygem-json_spec.git /var/lib/mock/f38-build-side-42-init-devel-583554-26087/root/chroot_tmpdir/scmroot/rubygem-json_spec
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-583554-26087/root/chroot_tmpdir/scmroot/rubygem-json_spec'...
$ git fetch origin 4280c099c145dcf0796e364b7506e7fe0e19fe2a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-json_spec
 * [new ref]         4280c099c145dcf0796e364b7506e7fe0e19fe2a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4280c09 Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild