$ git clone -n https://src.fedoraproject.org/rpms/rust-tokio-executor.git /var/lib/mock/f41-build-side-1-3134952-39764/root/chroot_tmpdir/scmroot/rust-tokio-executor
Cloning into '/var/lib/mock/f41-build-side-1-3134952-39764/root/chroot_tmpdir/scmroot/rust-tokio-executor'...
$ git fetch origin 295be9608c6b58a1e3791eea0eda0d5ce73b7441:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokio-executor
 * [new ref]         295be9608c6b58a1e3791eea0eda0d5ce73b7441 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 295be96 no longer needed