$ git clone -n https://src.fedoraproject.org/rpms/porcupine.git /var/lib/mock/f45-build-28910-634/root/chroot_tmpdir/scmroot/porcupine
Cloning into '/var/lib/mock/f45-build-28910-634/root/chroot_tmpdir/scmroot/porcupine'...
$ git fetch origin 07da363ed51c7f021b7b89da01ea1422d04c723e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/porcupine
 * [new ref]         07da363ed51c7f021b7b89da01ea1422d04c723e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 07da363 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild