$ git clone -n https://src.fedoraproject.org/rpms/rust-nu-explore.git /var/lib/mock/f40-build-2667042-67140/root/chroot_tmpdir/scmroot/rust-nu-explore
Cloning into '/var/lib/mock/f40-build-2667042-67140/root/chroot_tmpdir/scmroot/rust-nu-explore'...
$ git fetch origin f869f4000113a5338b608b5eb5343465202d0a36:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-nu-explore
 * [new ref]         f869f4000113a5338b608b5eb5343465202d0a36 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f869f40 Update to 0.91.0 (rhbz#2257504)