Recipe

The function of a recipe is to describe how to deterministically fetch or build software. One recipe normally represents one application or library. There are four types of recipes in Chariot:

  • Source — describes how to fetch and prepare, normally software source code, files.
  • Tool — describes how to build software for use by other recipes.
  • Package — describes how to build software for the target operating system being bootstrapped.
  • Custom — describes how to build software for an unspecified/custom purpose.

Every recipe consists of its type, name, and a set of options. All recipes allow the following options:

NameDescription
optionsThe user defined options used by this recipe.
dependenciesList of dependencies.
See type specific options.

User Defined Options

User defined options are not to be confused with recipe options.

Users can define options using the option directive. The options can be set on the command line as described in the CLI section. Recipes can then "subscribe" to relevant options and can use the values passed to influence the recipe.

A recipe that has "subscribed" to an option will create distinct builds per option set. Note that recipes that depend on these recipes will also create distinct builds for those options.

For example, take this configuration:
```
@option "buildtype" = [ "debug", "release" ]

package/xyz {
    options: [ "buildtype" ]
    ...
}
```
The xyz package will have a distinct build for both debug and release build types.

Recipes can also choose the allowed values for chosen options. This functionality is useful when combined with the optional modifier on a dependency.

```
package/xyz {
    options: [ "buildtype" = [ "release" ] ]
    ...
}
```
In this case the xyz package will fail to build for any other values of buildtype than debug.

Dependency

A dependency is made up of modifiers, a namespace, and a name. It takes the form of:

<modifier(s)><namespace>/<name>

The valid namespaces are:

  • source refers to a source recipe.
  • tool refers to a tool recipe.
  • package refers to a package recipe.
  • custom refers to a custom recipe.
  • image refers to an image package.
  • collection refers to a collection. Collections are defined by the collection directive.

The valid modifiers are:

ModifierSymbolApplies ToDescription
Runtime*AllDependency is needed at runtime, not just build time.
Optional?AllAllow the recipe to build even if the dependency cannot be fulfilled. This can happen if the dependency does not support an option value.
Mutable%Source onlySource directory can be modified during build. Note that the modifications will not persist after the build.
Loose!AllDependency will not invalidate its parent.
Usage of the loose discouraged. It is hacky and only meant for use in severe circumstances.

```
%source/libtool
tool/autoconf
image/build-essential
```