$ git clone -n https://src.fedoraproject.org/rpms/R-callr.git /var/lib/mock/f40-build-2321211-58550/root/chroot_tmpdir/scmroot/R-callr
Cloning into '/var/lib/mock/f40-build-2321211-58550/root/chroot_tmpdir/scmroot/R-callr'...
$ git fetch origin a0ec3f1037bdf334b4c57cfbb114632845083872:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-callr
 * [new ref]         a0ec3f1037bdf334b4c57cfbb114632845083872 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a0ec3f1 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild