$ git clone -n https://src.fedoraproject.org/rpms/R-R.devices.git /var/lib/mock/f45-build-5911-345/root/chroot_tmpdir/scmroot/R-R.devices
Cloning into '/var/lib/mock/f45-build-5911-345/root/chroot_tmpdir/scmroot/R-R.devices'...
$ git fetch origin 140de51378d80fc463b2de0c2548c287aac00380:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-R.devices
 * [new ref]         140de51378d80fc463b2de0c2548c287aac00380 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 140de51 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild