$ git clone -n https://src.fedoraproject.org/rpms/rust-signal-hook-mio.git /var/lib/mock/f39-build-1517162-35693/root/chroot_tmpdir/scmroot/rust-signal-hook-mio
Cloning into '/var/lib/mock/f39-build-1517162-35693/root/chroot_tmpdir/scmroot/rust-signal-hook-mio'...
$ git fetch origin b1ee6e7d346d6f186c30712a43e4abffb60b2495:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-signal-hook-mio
 * [new ref]         b1ee6e7d346d6f186c30712a43e4abffb60b2495 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1ee6e7 Regenerate with rust2rpm v24