How to disable stack with flycheck for Haskell?

Question

I'm on nixos and due to stack's integration with Nix/Nixos the following command is very slow:

time stack ghc
ghc: no input files
Usage: For basic information, try the `--help' option.
stack ghc  1.14s user 0.13s system 95% cpu 1.324 total

This means after a few keystrokes the emacs editor hangs... So I usually uninstall stack to remove it from the $PATH.

How can I disable this, to avoid this really frustrating delay?

In the messages:

haskell-stack-ghc: Flycheck checker haskell-stack-ghc returned non-zero exit code 1,

I have tried adding:

(add-to-list '(flycheck-disabled-checkers '(haskell-stack-ghc)))

to my init file, but there was no change in behavior.

Answer 1

(add-to-list 'flycheck-disabled-checkers 'haskell-stack-ghc)

The first argument to add-to-list is the name (more precisely the symbol) of the variable to modify. The second argument is the element (here again a symbol) to add. Both symbols need to be quoted since you need to pass the symbol itself to the function and not the value that the variable is bound to.

Answer 2

(setq-default flycheck-disabled-checkers '(haskell-stack-ghc))

I had to set the above...