haskell-nix.cabalProject trying to access network in derivation

[picnoir]

Hi,

Not sure whether this is a documentation problem or an actual haskell.nix bug, but I'm having some issues using cabalProject on the current master.

It looks like the produced derivation is trying to access the network outside of a FOD.

I created a minimal repro here: https://git.alternativebit.fr/NinjaTrappeur/haskellNixRepro.cabalProject_bug_repro/src/commit/6ac441f96acf6baee96dc365a00ff7c0f547f695

I'm not familiar with this project's internals, any idea about what's happening there?

[angerman]

You are using a source repository. As cabalProject discovers this during the build it will need some additional assistance with that.

You can provide a cache argument. Like here

haskell.nix/examples/cardano-wallet-args.nix

Line 23 in b8af990

cache = [

Cache for stack and cabal projects should be the same.

[hamishmack]

An alternative to using a cache argument is to add the nix hash to a comment in the cabal.project file:

source-repository-package
  type: git
  location: http://github.com/well-typed/canonical-json
  tag: ddfe3593b80b5ceb88842bb7a6f2268df75d2c2f
  --sha256: 02fzn1xskis1lc1pkz0j92v6ipd89ww0k2p3dvwpm3yap5dpnm7k

[picnoir]

Thanks for the quick answer!

I tried to use the cache argument without success. It seems to be ignored by cabalProject. The sha256 comment in the cabal.project file does work though!

I had a naive shot to make the cache argument work at picnoir@9e8a171 . The cache argument still gets ignored. I'm probably missing something and don't have enough time to dive into this rabbit hole at the moment.

I opened a PR #373 adding this sha256 comment trick to the readme file. It might prevent other people from being confused by this :)

[angerman]

@NinjaTrappeur intersting find. I could have sworn we had cache support for cabalProjects as well. 😕