Tweak sigh to stop double output of errors from tsc (#3003)
Tweak sigh to stop double output of errors from tsc (#3003)


PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs