$ git clone -n https://src.fedoraproject.org/rpms/bst-external.git /var/lib/mock/f42-build-3182011-40950/root/chroot_tmpdir/scmroot/bst-external
Cloning into '/var/lib/mock/f42-build-3182011-40950/root/chroot_tmpdir/scmroot/bst-external'...
$ git fetch origin 21cbc9985a7401fce0b966fe1817410de4c282df:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bst-external
 * [new ref]         21cbc9985a7401fce0b966fe1817410de4c282df -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21cbc99 Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild