The easiest way to get a working idris version is to install the `idris` attribute:
```
$ # On NixOS
$ nix-env -i nixos.idris
$ # On non-NixOS
$ nix-env -i nixpkgs.idris
```
This however only provides the `prelude` and `base` libraries. To install idris with additional libraries, you can use the `idrisPackages.with-packages` function, e.g. in an overlay in `~/.config/nixpkgs/overlays/my-idris.nix`:
```nix
self: super: {
myIdris = with self.idrisPackages; with-packages [ contrib pruviloj ];
in another file (say `default.nix`) to be able to build it with
```
$ nix-build -A yaml
```
## Passing options to `idris` commands
The `build-idris-package` function provides also optional input values to set additional options for the used `idris` commands.
Specifically, you can set `idrisBuildOptions`, `idrisTestOptions`, `idrisInstallOptions` and `idrisDocOptions` to provide additional options to the `idris` command respectively when building, testing, installing and generating docs for your package.
For example you could set
```
build-idris-package {
idrisBuildOptions = [ "--log" "1" "--verbose" ]
...
}
```
to require verbose output during `idris` build phase.