$ git clone -n https://src.fedoraproject.org/rpms/gumbo-parser.git /var/lib/mock/f39-build-1470154-33882/root/chroot_tmpdir/scmroot/gumbo-parser
Cloning into '/var/lib/mock/f39-build-1470154-33882/root/chroot_tmpdir/scmroot/gumbo-parser'...
$ git fetch origin b2339d38479c6a48f3ef2bca1effac00304192ce:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gumbo-parser
 * [new ref]         b2339d38479c6a48f3ef2bca1effac00304192ce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2339d3 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild