History

zowoq 8adc564f28 treewide: editorconfig fixes - add final newline - use spaces for indentation		2021-01-21 09:30:52 +10:00
..
packages	treewide: editorconfig fixes	2021-01-21 09:30:52 +10:00
default.nix	elmPackages.*: add meta	2021-01-16 19:48:00 +01:00
fetchElmDeps.nix	Elm: 0.19.0 -> 0.19.1	2019-10-21 21:32:35 +02:00
makeDotElm.nix	makeDotElm: fix	2020-05-03 21:54:20 +03:00
README.md	Elm: automate packaging with elm2nix	2019-01-03 16:37:09 +00:00
registry.dat	Elm: 0.19.0 -> 0.19.1	2019-10-21 21:32:35 +02:00
update.sh	Elm: 0.19.0 -> 0.19.1	2019-10-21 21:32:35 +02:00

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/