$ git clone -n https://src.fedoraproject.org/rpms/rust-difftastic.git /var/lib/mock/f38-build-side-43-rust-devel-1403713-31199/root/chroot_tmpdir/scmroot/rust-difftastic
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1403713-31199/root/chroot_tmpdir/scmroot/rust-difftastic'...
$ git fetch origin 42f64534f14d48c214460333c9e4463f97ce0e1a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-difftastic
 * [new ref]         42f64534f14d48c214460333c9e4463f97ce0e1a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 42f6453 Update to 0.51.1