gaz factory – literally translaited from a French phrase “usine a gaz” which refers to a system or machine that is super-complex

Our software build system has a lot of external dependencies and is so complex that whoever works on it must get confused. A French colleague says there is a French term to descibe it -  literally translated as “Gaz Factory“. I don’t speak French, but I like this expression. It is easy to picture such a factory where machines are messed around and with all the notice, gas, smoke in the background. However, he doesn’t know the English equivalent; neither do I (In fact, I don’t know if there is a Chinese equivalent that is as vivid as this). Does anyone know if there is a similar expression in English? Apparently, I’m not the first one who asks this question.