Found a little bug while playing Alarak in coop.
When you morph a Gateway into a Warpgate while producing a unit(Havoc in my case) the production of the unit does not get canceled, just stopped, so its still building but will not finish as long as the Gateway is still a Warpgate. It does continue to be build after being morphed back, but can no longer be canceled since its no longer tracked. Why do I consider it a bug? Resources and supply is permanently gone as long as the unit is still in suspended production, people might miss that.
Basically, build Warpgate, build Havoc, while building, morph into Warpgate to reproduce the bug. Easy fix: Auto cancel anything while morphing or dont let it morph while its still building something.
Might also apply in other situations, gotta test that.