$ git clone -n https://src.fedoraproject.org/rpms/python-specfile.git /var/lib/mock/f42-build-side-1-3499882-45966/root/chroot_tmpdir/scmroot/python-specfile
Cloning into '/var/lib/mock/f42-build-side-1-3499882-45966/root/chroot_tmpdir/scmroot/python-specfile'...
$ git fetch origin 6fd040e9681c27257f01ac64171bfa5623f6b7b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-specfile
 * [new ref]         6fd040e9681c27257f01ac64171bfa5623f6b7b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6fd040e Update to 0.35.0 upstream release