[question] Can't build with cabal using the JS backend
I'm trying to build a project using the JS backend in GHC 9.6 (or 9.7.20230406). I'm getting GHC from nixpkgs (pkgsCross.ghcjs.haskell.compiler.ghc96
) and running this command:
cabal --with-compiler=javascript-unknown-ghcjs-ghc --with-ghc-pkg=javascript-unknown-ghcjs-ghc-pkg build
This eventually fails to build lens
, because ghcjs_HOST_OS
is not set, and this file relies on it. Setting --ghc-option='-Dghcjs_HOST_OS'
doesn't change anything.
So I tried this instead:
cabal --ghcjs --with-ghcjs=javascript-unknown-ghcjs-ghc --with-ghcjs-pkg=javascript-unknown-ghcjs-ghc-pkg build
Which now complains that it can't determine the version of javascript-unknown-ghcjs-ghc
. And indeed, Cabal is trying to run javascript-unknown-ghcjs-ghc --numeric-ghcjs-version
, which is not a recognised flag.
How do I use the new JS backend with Cabal?