A short list off the top of my head: It is very easy to get over eager and use more abstraction than you need or can handle. This is perhaps the worst of them.

A short list off the top of my head: It is very easy to get over eager and use more abstraction than you need or can handle. This is perhaps the worst of them. Strings shouldn't be [Char]. OverloadedStrings should be the default. There are partial functions in base. head for example It is easy to spring space leaks due to laziness. Relatedly, choosing between foldr foldl foldl' Incomplete pattern matching (which will be a warning) or sometimes default _ casing. If you add to the type, the compiler won't save you. It is not necessarily so obvious to a beginner when you are doing tail call recursion. Maybe overuse of typeclasses when records work better? Over use of Template Haskell can raise an eyebrow. A minority of extensions are ill advised. All in all, I think the level of footguns in Haskell is in a different universe than C++, but I am trying to see it from the other perspective. http://dev.stephendiehl.com/hask/#what-to-avoid http://dev.stephendiehl.com/hask/#what-to-avoid http://dev.stephendiehl.com/hask/#the-dangerous http://dev.stephendiehl.com/hask/#the-dangerous