$ git clone -n https://src.fedoraproject.org/rpms/R-whisker.git /var/lib/mock/f45-build-6521-349/root/chroot_tmpdir/scmroot/R-whisker
Cloning into '/var/lib/mock/f45-build-6521-349/root/chroot_tmpdir/scmroot/R-whisker'...
$ git fetch origin 660245dca441c203973ddb9d8508bd0dc6276716:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-whisker
 * [new ref]         660245dca441c203973ddb9d8508bd0dc6276716 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 660245d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild