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

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

devshell.mkShell ({ extraModulesPath, ... }: {
  imports = ["${extraModulesPath}/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.