Hey!
Could be a rare case, but when I was analyzing code I noticed, that when you `void Production::startItem(Base * b, SavedGame * g, const Mod *m) const` and your project require the craft, it would be removed and deleted. But when we look to `refundItem`, we can see that there is no way to refund the craft in case we abort construction.
I understand how coplicated proper handling of this case, you can stuck with no free hangar space. But may be at least warn the player about consequences?