$ git clone -n https://src.fedoraproject.org/rpms/rust-async-io.git /var/lib/mock/f40-build-2507309-61702/root/chroot_tmpdir/scmroot/rust-async-io
Cloning into '/var/lib/mock/f40-build-2507309-61702/root/chroot_tmpdir/scmroot/rust-async-io'...
$ git fetch origin a48825bd92f1e834162c591e1ae461486b2260e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-async-io
 * [new ref]         a48825bd92f1e834162c591e1ae461486b2260e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a48825b Update to version 2.3.1; Fixes RHBZ#2258541