$ git clone -n https://src.fedoraproject.org/rpms/rust-tiff.git /var/lib/mock/f38-build-side-42-init-devel-1395941-31050/root/chroot_tmpdir/scmroot/rust-tiff
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1395941-31050/root/chroot_tmpdir/scmroot/rust-tiff'...
$ git fetch origin 17dcf1a081995a0f6a5b49b0285db7863dedd1e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tiff
 * [new ref]         17dcf1a081995a0f6a5b49b0285db7863dedd1e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 17dcf1a Update to version 0.9.0; Fixes RHBZ#2138521