$ git clone -n https://src.fedoraproject.org/rpms/rust-mio.git /var/lib/mock/f40-build-2123308-50753/root/chroot_tmpdir/scmroot/rust-mio
Cloning into '/var/lib/mock/f40-build-2123308-50753/root/chroot_tmpdir/scmroot/rust-mio'...
$ git fetch origin 6986cb4a8b43574fce2cd4ff3fca4e1ce4029b30:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-mio
 * [new ref]         6986cb4a8b43574fce2cd4ff3fca4e1ce4029b30 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6986cb4 Update to version 0.8.9; Fixes RHBZ#2245636