$ git clone -n https://src.fedoraproject.org/rpms/rubygem-clutter.git /var/lib/mock/f39-build-1502491-34923/root/chroot_tmpdir/scmroot/rubygem-clutter
Cloning into '/var/lib/mock/f39-build-1502491-34923/root/chroot_tmpdir/scmroot/rubygem-clutter'...
$ git fetch origin edf197c5694ebf51886b5e2268eecab9e3e83454:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-clutter
 * [new ref]         edf197c5694ebf51886b5e2268eecab9e3e83454 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at edf197c 4.2.0 entry