$ git clone -n https://src.fedoraproject.org/rpms/rust-open.git /var/lib/mock/f45-build-43530-803/root/chroot_tmpdir/scmroot/rust-open
Cloning into '/var/lib/mock/f45-build-43530-803/root/chroot_tmpdir/scmroot/rust-open'...
$ git fetch origin a2f9e358f8f9a8250ae520a962fcc47e590b6130:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-open
 * [new ref]         a2f9e358f8f9a8250ae520a962fcc47e590b6130 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a2f9e35 Update to version 5.4.2; Fixes RHBZ#2521827