$ git clone -n https://src.fedoraproject.org/rpms/rubygem-pango.git /var/lib/mock/f41-build-855368-167117/root/chroot_tmpdir/scmroot/rubygem-pango
Cloning into '/var/lib/mock/f41-build-855368-167117/root/chroot_tmpdir/scmroot/rubygem-pango'...
$ git fetch origin 590a7473bd0e006ce945e7545e5e922b859a2a94:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-pango
 * [new ref]         590a7473bd0e006ce945e7545e5e922b859a2a94 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 590a747 4.2.3 entry