How to exploit ./hadrian/ghci to find errors quickly?

Norman Ramsey nr at
Fri Jan 28 21:45:14 UTC 2022

 > This is the typical use case for a language server.
 > I have haskell-language-server installed and use it extensively on GHC 
 > for stuff like jump to definition and immediate compilation feedback.

I would *love* to be doing this.  I have had HLS installed on my
machine for months, and have been using with Emacs.  But to say I have
trouble getting it work as advertised is an understatement.

For example, on the module I'm trying to diagnose, I'm getting just
one error message, on the first line:

  Data.Binary.Get.runGet at position 1844: not enough bytes

 > There's also "jump to next error" if you want that.

I can't find it using either "C-h f" or using the list of keybindings
at  I think it
might be supported by flycheck, but "C-x `" simply says "No more
Flycheck errors."

In general, my experience is "sometimes it works and sometimes it
doesn't."  Even for things as simple as "M-." (find definition).

If you know of any resources on using HLS with GHC, I'd love to be
directed.  For example, when Emacs asks if I really want to watch
circa 5,000 directories, do I say "yes"?

 > The hour or so I invested on initial setup has probably saved me several 
 > days already.

I am **so eager** to get there.  But definitely not there yet.


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