$ git clone -n https://src.fedoraproject.org/rpms/xen.git /var/lib/mock/f42-bootstrap-3463010-45594/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/f42-bootstrap-3463010-45594/root/chroot_tmpdir/scmroot/xen'...
$ git fetch origin 59fe5ad165212ec0c53c231b3a0edf8e88b5c5d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xen
 * [new ref]         59fe5ad165212ec0c53c231b3a0edf8e88b5c5d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 59fe5ad deadlock potential with VT-d and legacy PCI device pass-through