extending.md

Extending devshell

When the base modules that are provided by devshell are not enough, it is possible to extend it.

Extra modules

All the devshell.toml schema options that are Declared in: the extra/ folder in the schema documentation are loaded on demand.

In order to load an extra module, use the <name> in the import section. For example to make the locale options available, import locale:

devshell.toml:

imports = ["locale"]

Make sure to add this at the first statement in the file.

Now that the module has been loaded, the devshell.toml understands the locale prefix:

imports = ["locale"]

[locale]
lang = "en_US.UTF-8"

From a nix flake you would import it like

imports = ["${devshell}/extra/locale.nix"];

Building your own modules

Building your own modules requires to understand the Nix language. If this is too complicated, please reach out to the issue tracker and describe your use-case. We want to be able to support a wide variety of development scenario.

In the same way as previously introduced, devshell will also load files that are relative to the devshell.toml. For example:

imports = ["mymodule.nix"]

Will load the mymodule.nix file in the project repository and extend the devshell.toml schema accordingly.