What Gets Built

During the evaluation stage, NixCI discovers which flake outputs exist and schedules build jobs for each. This page explains which outputs get built.

For an overview of how NixCI processes commits, see How It Works .

NixCI builds the following flake outputs, in this order:

1. devShell
2. devShells
3. formatter
4. packages
5. checks

You can control which systems and outputs get excluded in your NixCI configuration .

Given a flake with these outputs for x86_64-linux :

{
  devShell.x86_64-linux = ...;
  devShells.x86_64-linux.default = ...;
  formatter.x86_64-linux = ...;
  packages.x86_64-linux.default = ...;
  packages.x86_64-linux.my-app = ...;
  checks.x86_64-linux.lint = ...;
  checks.x86_64-linux.tests = ...;
}

NixCI will create these build runs:

1. devShell.x86_64-linux
2. devShells.x86_64-linux.default
3. formatter.x86_64-linux
4. packages.x86_64-linux.default
5. packages.x86_64-linux.my-app
6. checks.x86_64-linux.lint
7. checks.x86_64-linux.tests

NixCI does not build nixosConfigurations directly because the architecture cannot be determined automatically. To build a NixOS configuration, expose it as a check:

checks.x86_64-linux.my-machine =
  nixosConfigurations.my-machine.config.system.build.toplevel;

In addition to build jobs, NixCI can run impure tests and continuous deployment jobs. These are configured separately and run after builds complete.