$ git clone -n https://src.fedoraproject.org/rpms/R-R.oo.git /var/lib/mock/f45-build-5903-345/root/chroot_tmpdir/scmroot/R-R.oo
Cloning into '/var/lib/mock/f45-build-5903-345/root/chroot_tmpdir/scmroot/R-R.oo'...
$ git fetch origin 9da2361e99a031610d971377ae317208f0afa0ff:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-R.oo
 * [new ref]         9da2361e99a031610d971377ae317208f0afa0ff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9da2361 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild