$ git clone -n https://src.fedoraproject.org/rpms/python-nbclient.git /var/lib/mock/f42-build-3490768-45854/root/chroot_tmpdir/scmroot/python-nbclient
Cloning into '/var/lib/mock/f42-build-3490768-45854/root/chroot_tmpdir/scmroot/python-nbclient'...
$ git fetch origin 50f7f43d86b1be76013cbf83313dd2e40e2cd7e5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-nbclient
 * [new ref]         50f7f43d86b1be76013cbf83313dd2e40e2cd7e5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 50f7f43 Introduce a bootstrap bcond to allow EPEL build inside side tags.