How to configure stack for most recent ghcjs / lts build

Question

The stack docs gives example configurations for compiling with ghcjs https://docs.haskellstack.org/en/stable/ghcjs/ . But the latest example is with lts-7.19. I'd like to configure stack to use the latest ghcjs possible with the latest lts (currently 8.4).

I understand that the ghcjs compiler is prepackaged for each lts and hosted by https://github.com/tolysz/ , using https://github.com/tolysz/prepare-ghcjs . I suppose my real question is:

How can I find out what possible versions are available at ghcjs.tolysz.org (along with their sha1 hashes)?

EDIT: So far I have found that you can view untested builds here: http://tolysz.org/ghcjs/untested/ but they are indeed untested, and the ones I have tried do not work. I've tried building my own with prepare-ghcjs but with no success - recent changes in ghcjs have not yet been allowed for in prepare-ghcjs, so I'm trying to put something together there https://github.com/tolysz/prepare-ghcjs/issues/6 .

Answer 1

The short answer is that there is no straightforward way to do this. However, I have forked ghcjs, ghcjs-base and ghcjs-boot, altered a few patches and so forth and put together a working archive for use with stack. I've raised a thread about this in haskell-stack, but no response yet.

For the time being, I have put up a git repo ghcjs-stack-dist containing prepacked distributions of ghcjs ready for use with stack lts-8.0 and lts-8.5. Please see the repo readme for information on usage.