called with unexpected argument '__functor'

[hamishmack]

This is likely to be a common issue for people upgrading to the latest version of haskell.nix.

If you get an error like this after updating then the simplest fix is to update the nix
code to use the new API.

For example you may need to go from:

pkgs = import nixpkgsSrc (import haskellNixSrc);

to

pkgs = import nixpkgsSrc ((import haskellNixSrc {}).nixpkgsArgs);

You will need both the addition of {} and the use of .nixpkgsArgs.

[locallycompact]

I'm trying to fix this error with a stack-to-nix setup like shown here (which has a small typo btw)

https://input-output-hk.github.io/haskell.nix/user-guide/stack-projects/#creating-the-package-set

but then I get the error

error: attempt to call something which is not a function but a string with context, at /home/lc/Source/gitlab.com/shakebook-site/shakebook-site.gitlab.io/nix/default.nix:5:13

[hamishmack]

Thanks for the heads up. As well as the typo there were some places import was missing and that looks likely to have caused your issue. I have fixed up the docs with #543.

[hamishmack]

Now the V1 interface is gone we will not see any more of these (with the latest haskell.nix), but we may see #709 instead.