nixpkgs/pkgs/development/compilers/elm
Alexander Foremny 3d88f74c9d elmPackages.elmi-to-json: build using aeson 1.5.6.0
elmi-to-json (and others) did not build as aeson 2.0.3.0 fails to build
with attoparsec < 0.14, presumably since
376a511e09.
2022-04-07 08:54:24 +02:00
..
packages elmPackages: update nodejs dependecies 2022-04-02 19:36:33 +02:00
default.nix elmPackages.elmi-to-json: build using aeson 1.5.6.0 2022-04-07 08:54:24 +02:00
fetchElmDeps.nix
makeDotElm.nix
README.md
registry.dat
update.sh

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/