$ git clone -n https://src.fedoraproject.org/rpms/rust-remain.git /var/lib/mock/f40-build-2307707-57243/root/chroot_tmpdir/scmroot/rust-remain
Cloning into '/var/lib/mock/f40-build-2307707-57243/root/chroot_tmpdir/scmroot/rust-remain'...
$ git fetch origin 55771a083671cc3ddeb7ca2173284185c1e648eb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-remain
 * [new ref]         55771a083671cc3ddeb7ca2173284185c1e648eb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 55771a0 Update to version 0.2.12; Fixes RHBZ#2256426