I've just installed haskell-platform from the Ubuntu repositories (it comes with GHC version 8.6.5) as instructed by the website. Now, upon trying to compile a program for profiling, using ghc -O2 -prof myCode.hs, I'm met with the following error message:

myCode.hs:1:1: error: 
    Could not find module ‘Prelude’
    Perhaps you haven't installed the profiling libraries for package ‘base-4.12.0.0’?

and similarly for the System.IO module.

Should they not come with the default Haskell instalation? How can I proceed? Perhaps I should purge it all and get Haskell form another source (Stack, Ghcup, etc? Should it matter?)

I'm fairly new to this, so any help is appreciated.

CodePudding user response：

On Ubuntu, essentially all of the Haskell packages come in bland and -prof flavors. You need the latter for profiling.

ghcup is also fine. There's no need to purge it all -- ghcup and the package manager can coexist cleanly.