$ git clone -n https://src.fedoraproject.org/rpms/rust-tokio-sync.git /var/lib/mock/f41-build-side-1-3129196-39576/root/chroot_tmpdir/scmroot/rust-tokio-sync
Cloning into '/var/lib/mock/f41-build-side-1-3129196-39576/root/chroot_tmpdir/scmroot/rust-tokio-sync'...
$ git fetch origin 38d06fce93beca3d4e5ae01d35a80b206c5fc2e9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokio-sync
 * [new ref]         38d06fce93beca3d4e5ae01d35a80b206c5fc2e9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 38d06fc no longer needed