$ git clone -n https://src.fedoraproject.org/rpms/R-mockr.git /var/lib/mock/f39-build-1544819-36669/root/chroot_tmpdir/scmroot/R-mockr
Cloning into '/var/lib/mock/f39-build-1544819-36669/root/chroot_tmpdir/scmroot/R-mockr'...
$ git fetch origin 868b34ec013c20f7bedb2de969583c8daa75d343:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-mockr
 * [new ref]         868b34ec013c20f7bedb2de969583c8daa75d343 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 868b34e Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild