$ git clone -n https://src.fedoraproject.org/rpms/rust-minus.git /var/lib/mock/f39-build-1795620-41755/root/chroot_tmpdir/scmroot/rust-minus
Cloning into '/var/lib/mock/f39-build-1795620-41755/root/chroot_tmpdir/scmroot/rust-minus'...
$ git fetch origin ab6382934209dfa17cfbcf95f9cd913d5aa136a7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-minus
 * [new ref]         ab6382934209dfa17cfbcf95f9cd913d5aa136a7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ab63829 Update to version 5.4.2; Fixes RHBZ#2244685