A phrase similar to "...is the mother of all f##k ups!"

Question

So I was fixing some code (because someone thought they were smart enough to start using multiple inheritance and I guess "Kernighan's lever" came into effect) and I want to add a comment "Remember kids multiple inheritance is the mother of all f##k ups!" (I know it's usually "Assumption is the mother of all f##k ups!")

Is there a similar phrase in Japanese? If not; how would I write this to convey the same connotation?

Answer 1

「諸悪｛しょあく｝の根源｛こんげん｝」 , a very common phrase (but without any profanity), is fairly close to "mother of all xxxx-ups" both in meaning and feeling. Thus, you could say:

「Noun + こそ + 諸悪の根源である。」

"Multiple inheritance" would be 「多重継承{たじゅうけいしょう}」.

"Assumption" would be 「決{き}めつけ」.