$ git clone -n https://src.fedoraproject.org/rpms/nexus.git /var/lib/mock/f41-build-1029528-18396/root/chroot_tmpdir/scmroot/nexus
Cloning into '/var/lib/mock/f41-build-1029528-18396/root/chroot_tmpdir/scmroot/nexus'...
$ git fetch origin 542cfb529cd911160c830174d5ef1fe07d2f2f88:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nexus
 * [new ref]         542cfb529cd911160c830174d5ef1fe07d2f2f88 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 542cfb5 Eliminate use of obsolete %patchN syntax (#2283636)