Ok, added as a feature request. http://hackage.haskell.org/trac/ghc/ticket/1921#preview Simon Peyton-Jones wrote:
| So, my suggestion is that in any case where the compiler currently | suggests use of a particular pragma in an error message, it should | instead turn that pragma on and produce a warning.
In the cases where the compiler makes that suggestion, yes what you suggest would be feasible I think. But it would be patchy and ad hoc -- often the compiler would "do the right thing" (at least as you see it), but sometimes not.
Nevertheless, patchy and ad-hoc solutions are sometimes very convenient. I certainly agree that messages of the form "bad programmer, you clearly meant X but you didn't *write* X; so go write X and then I'll compile your program" are tiresome.
Why not make it a feature request and try to get people to vote for it (by adding themselves to the cc list and/or adding comments)?
Simon