$ git clone -n https://src.fedoraproject.org/rpms/R-rprojroot.git /var/lib/mock/f39-build-1586929-38213/root/chroot_tmpdir/scmroot/R-rprojroot
Cloning into '/var/lib/mock/f39-build-1586929-38213/root/chroot_tmpdir/scmroot/R-rprojroot'...
$ git fetch origin 8c60297b53b1323cc8b291ffc794a10c4f30fd43:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-rprojroot
 * [new ref]         8c60297b53b1323cc8b291ffc794a10c4f30fd43 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8c60297 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild