History

Frederik Rietdijk 26335f358e elm: don't import <nixpkgs>, fixes tarball job Don't import <nixpkgs>, because that is not allowed. Broken by https://github.com/NixOS/nixpkgs/pull/63477 cc @turboMaCk		2019-06-25 16:14:56 +02:00
..
packages	elmPackages.{elm-test,elm-analyse..}: tooling additions and fixes	2019-06-18 21:29:10 +02:00
default.nix	elm: don't import <nixpkgs>, fixes tarball job	2019-06-25 16:14:56 +02:00
fetchElmDeps.nix
makeDotElm.nix
README.md
update.sh
versions.dat

README.md

To update Elm:

Modify revision in ./update.sh and run it

Notes about the build process:

The elm binary embeds a piece of pre-compiled elm code, used by 'elm reactor'. This means that the build process for 'elm' effectively executes 'elm make'. that in turn expects to retrieve the elm dependencies of that code (elm/core, etc.) from package.elm-lang.org, as well as a cached bit of metadata (versions.dat).

The makeDotElm function lets us retrieve these dependencies in the standard nix way. we have to copy them in (rather than symlink) and make them writable because the elm compiler writes other .dat files alongside the source code. versions.dat was produced during an impure build of this same code; the build complains that it can't update this cache, but continues past that warning.

Finally, we set ELM_HOME to point to these pre-fetched artifacts so that the default of ~/.elm isn't used.

More: https://blog.hercules-ci.com/elm/2019/01/03/elm2nix-0.1/