$ git clone -n https://src.fedoraproject.org/rpms/perl-Fsdb.git /var/lib/mock/f39-build-1441122-32372/root/chroot_tmpdir/scmroot/perl-Fsdb
Cloning into '/var/lib/mock/f39-build-1441122-32372/root/chroot_tmpdir/scmroot/perl-Fsdb'...
$ git fetch origin bd7436bba9a81429ac91d7ff3a5389fe20b4c9f4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Fsdb
 * [new ref]         bd7436bba9a81429ac91d7ff3a5389fe20b4c9f4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bd7436b release 3.3