$ git clone -n https://src.fedoraproject.org/rpms/apache-commons-io.git /var/lib/mock/f42-build-3360759-45036/root/chroot_tmpdir/scmroot/apache-commons-io
Cloning into '/var/lib/mock/f42-build-3360759-45036/root/chroot_tmpdir/scmroot/apache-commons-io'...
$ git fetch origin 7dda3bb96ff6dd6c7f2a9c7f87ee4f80a53de37f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/apache-commons-io
 * [new ref]         7dda3bb96ff6dd6c7f2a9c7f87ee4f80a53de37f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7dda3bb Fix javadoc obsoletes version