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Join our community on Discord to discuss the development of devenv.

When contributing, please note that smaller pull requests have a higher chance of being accepted, and pull requests with tests will be prioritized.

We have a rule that new features need to come with documentation and tests (devenv-run-tests) to ensure the project stays healthy.

Preparing the devenv development environment

  1. Follow the installation instructions for Nix and Cachix and install direnv.

  2. git clone

  3. cd devenv

  4. To build the project, run direnv allow . or build devenv manually using nix build .#devenv which allows to run development version of devenv outside of source code directory by calling <PATH-TO-DEVENV-SOURCE-CODE>/result/bin/devenv.

Creating development project

  1. mkdir devenv-project && cd devenv-project

  2. <PATH-TO-DEVENV-SOURCE-CODE>/result/bin/devenv init

  3. Add devenv input pointing to local source directory to devenv.yaml

      url: path:<PATH-TO-DEVENV-SOURCE-CODE>?dir=src/modules

  4. <PATH-TO-DEVENV-SOURCE-CODE>/result/bin/devenv update

Repository structure

  • The devenv CLI is in devenv/src/
  • The flake.nix auto-generation logic lies in devenv/src/flake.tmpl.nix.
  • All modules related to devenv.nix are in src/modules/.
  • Examples are automatically tested on CI and are the best way to work on developing new modules, see examples/ and tests/
  • Documentation is in docs/.
  • To run a development server, run devenv up.
  • To run a test, run devenv-run-tests --only <example-name> examples.

Contributing language improvements

Language integration happens in stages. We welcome even the most basic support for getting started.

The most basic language support starts with the languages.*.enable flag, which turns on basic tooling. For an example, see src/modules/languages/elm.nix.

The next step is to make the tooling customizable, so the versions can be overridden. Most languages will come with either a languages.*.package or languages.*.packages option that allows the user to customize what version or package of the language they want to pick.

A further step is to provide languages.*.version option, which allows the user to specify the exact version of the language. For an example, see src/modules/languages/rust.nix.