It fetches its Dart dependencies automatically through `pub2nix`, and (through a series of hooks) builds and installs the executables specified in the pubspec file. The hooks can be used in other derivations, if needed. The phases can also be overridden to do something different from installing binaries.
If the package has Git package dependencies, the hashes must be provided in the `gitHashes` set. If a hash is missing, an error message prompting you to add it will be shown.
The `depsListFile` must always be provided when packaging in Nixpkgs. It will be generated and printed if the derivation is attempted to be built without one. Alternatively, `autoDepsList` may be set to `true` only when outside of Nixpkgs, as it relies on import-from-derivation.
The `dart` commands run can be overridden through `pubGetScript` and `dartCompileCommand`, you can also add flags using `dartCompileFlags` or `dartJitFlags`.
Dart supports multiple [outputs types](https://dart.dev/tools/dart-compile#types-of-output), you can choose between them using `dartOutputType` (defaults to `exe`). If you want to override the binaries path or the source path they come from, you can use `dartEntryPoints`. Outputs that require a runtime will automatically be wrapped with the relevant runtime (`dartaotruntime` for `aot-snapshot`, `dart run` for `jit-snapshot` and `kernel`, `node` for `js`), this can be overridden through `dartRuntimeCommand`.
### Running executables from dev_dependencies {#ssec-dart-applications-build-tools}
Many Dart applications require executables from the `dev_dependencies` section in `pubspec.yaml` to be run before building them.
This can be done in `preBuild`, in one of two ways:
1. Packaging the tool with `buildDartApplication`, adding it to Nixpkgs, and running it like any other application
2. Running the tool from the Pub cache
Of these methods, the first is recommended when using a tool that does not need
to be of a specific version.
To use the second method, first make the derivation accessible within itself (e.g. `let self = ...; in self`), and then run it from the Pub cache in `preBuild`.