GHCJS resolver doesn't work

[novaluke]

Following the information here results in:

$ stack --version
Version 0.1.4.1 (UNKNOWN commits) X86_64
$ ghcjs --version
The Glorious Glasgow Haskell Compilation System for JavaScript, version 0.1.0 (GHC 7.10.2)
$ stack build --resolver ghcjs-0.1.0_ghc-7.10.2
No compiler found, expected minor version match with ghcjs-0.1.0_ghc-7.10.2 (x86_64) (based on resolver setting in /path/to/project/stack.yaml). Try running stack setup to locally install the correct GHC

On the other hand, using an invalid resolver value provides this message:

option --resolver: Invalid resolver value: foo. Possible valid values include lts-2.12, nightly-YYYY-MM-DD, ghc-7.10.2, and ghcjs-0.1.0-ghc-7.10.2.

So I tried to use the value given by the error message, but apparently using that resolver value does not work either:

$ stack build --resolver ghcjs-0.1.0-ghc-7.10.2
option --resolver: Invalid resolver value: ghcjs-0.1.0-ghc-7.10.2. Possible valid values include lts-2.12, nightly-YYYY-MM-DD, ghc-7.10.2, and ghcjs-0.1.0-ghc-7.10.2. See https://www.stackage.org/snapshots for a complete list.

[mgsloan]

The error message has been fixed in the development version, sorry about that 06d71e4

You need to have that version of GHCJS on your path, such that ghcjs --version reports that version. Then, it should work. stack setup is not yet supported for ghcjs, but the imminent plan is to have stack setup install things from source.

[novaluke]

Ah ok, that clears up which resolver value is the correct one, thanks.

I think (somewhat sheepishly) that perhaps my problem was not running ghcjs-boot before trying to use it with stack, since I've done that now and it's no longer complaining that it can't find the compiler. It's now complaining about finding dependencies, so I'm assuming that I've made it past the original issue in this thread. Thanks again!

[nrolland]

is there a guide/overview/reference on how to develop in ghcjs using stack ?

[mgsloan]

@nrolland Not yet, somewhat because "stack setup" didn't yet support it. However, that changed recently - #749 !

It's on my TODO list to add a template for GHCJS and write a guide on how to use it, good idea!

[nrolland]

Cool! Anything, however primitive would be useful to serve as a starting point and reference.

Stack and ghcjs are both very exciting pieces of the Haskell ecosystem.

[mgsloan]

A really quick tutorial would be:

Put this in your stack.yaml, next to the cabal file for your ghcjs project (just a standard cabal file)

resolver: ghcjs-0.1.0.20150924_ghc-7.10.2
compiler-check: match-exact

Run stack setup to install it (will take a while, it builds a lot of stuff). Then, stack build, and it should build. Then, you can find the output in the directory yielded by stack path --local-install-root