$ git clone -n https://src.fedoraproject.org/rpms/rust-conhash.git /var/lib/mock/f41-build-side-1-2991755-36005/root/chroot_tmpdir/scmroot/rust-conhash
Cloning into '/var/lib/mock/f41-build-side-1-2991755-36005/root/chroot_tmpdir/scmroot/rust-conhash'...
$ git fetch origin 61d0699348bce6b7d226eac07396abf7b8b9a86d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-conhash
 * [new ref]         61d0699348bce6b7d226eac07396abf7b8b9a86d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 61d0699 no longer needed