I use unagi with pvtbuild:
> Gaia:     `de3e5b9205e6cb1a6bd0858a98d159272ad96d11`
> Gecko:    http://hg.mozilla.org/releases/mozilla-b2g18/rev/99680a32f297
> BuildID   20130312070202
> Version   18.0

And the gaia was on v1-train, too.
> $ git branch --contains `de3e5b9205e6cb1a6bd0858a98d159272ad96d11`
> * v1-train