$ git clone -n https://src.fedoraproject.org/rpms/R-packrat.git /var/lib/mock/f38-build-side-42-init-devel-889334-28525/root/chroot_tmpdir/scmroot/R-packrat
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-889334-28525/root/chroot_tmpdir/scmroot/R-packrat'...
$ git fetch origin f3971ba06b1a7852c02ae2e177c652fccd39a695:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-packrat
 * [new ref]         f3971ba06b1a7852c02ae2e177c652fccd39a695 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f3971ba Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild