$ git clone -n https://src.fedoraproject.org/rpms/rubygem-memfs.git /var/lib/mock/f39-build-1499361-34744/root/chroot_tmpdir/scmroot/rubygem-memfs
Cloning into '/var/lib/mock/f39-build-1499361-34744/root/chroot_tmpdir/scmroot/rubygem-memfs'...
$ git fetch origin f600f7c8fe44c2f66e2535c40e2313b8d2865208:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-memfs
 * [new ref]         f600f7c8fe44c2f66e2535c40e2313b8d2865208 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f600f7c Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild