rom/docs

ROM

A Nix build output monitor for visualizing your Nix builds, with Rust characteristics and DX.

This project is heavily work in progress. The parser is mostly complete, and located in ./cognos

Note

This project is not yet stable. While it can not harm your projeeect, bugs must be expected due to its in-dev status. If you end up using ROM, please make sure to report any bugs :)

Usage

Warning

The CLI interface of ROM is not yet stable, and may be subject to change. Plase consult the --help output before reporting a bug.

$ rom -h
Rust Output Monitor - A Nix build output monitor

Usage: rom [OPTIONS] [COMMAND]

Commands:
  build    Run nix build with monitoring
  shell    Run nix shell with monitoring
  develop  Run nix develop with monitoring
  help     Print this message or the help of the given subcommand(s)

Options:
      --json             Parse JSON output from nix --log-format=internal-json
      --silent           Minimal output
      --format <FORMAT>  Output format: tree, plain [default: tree]
      --legend <LEGEND>  Legend display style: compact, table, verbose [default: table]
  -h, --help             Print help
  -V, --version          Print version

ROM is primarily designed to wrap the Nix installation on your system. As such, the recommended interface is using rom build, rom shell and rom develop for their Nix counterparts. The CLI of ROM is similar to NOM, the Haskell utility ROM is designed after. To build a package with Nix, let's say pkgs.hello, you can do:

$ rom build nixpkgs#hello
┏━ Dependency Graph:
┃ ⏵ hello-2.12.2 (configurePhase) ⏱ 2s
┣━━━ Builds
┗━ ∑ ⏵ 1 │ ✔ 0 │ ✗ 0 │ ⏸ 4 │ ⏱ 2s

and the dependency tree will appear below.

Argument Passthrough

At times, especially while you're calling ROM as a standalone executable, you might need to pass additional flags to the Nix command being invoked. ROM allows for this behaviour by accepting -- as a delimiter and passing any arguments that come after to Nix. For example:

$ rom develop nixpkgs#hello -- --substituters ""
fetching git input 'git+file:///home/notashelf/Dev/notashelf/rom'
┗━ ⏵ 0 │ ✔ 2 │ ✗ 0 │ ⏸ 0 │ ⏱ 1s


notashelf@enyo ~/Dev/notashelf/rom [git:(9e83f57...) *]
i $ hello
Hello, world!

FAQ

Q: If "NOM" is nix-output-monitor, what does "ROM stand for"?

A: It doesn't stand for anything, I named it rom beceuse it sounds like rum. I like rum. However you may choose to name it "rusty output monitor" or "raf's output monitor" at your convenience. I don't know, be creative.

Attributions

This project is clearly inspired by the famous https://github.com/maralorn/nix-output-monitor. I am a huge fan of NOM's design, but I am a little disappointed by its lack of configurability. This is a more flexible replacement that makes both my life, and displaying build graphs easier.

The ATerm and internal-json log parser was inspired, and mostly copied from https://git.atagen.co/atagen/nous with consolidation, cleaner repo layout, and a better separation of concerns. rom builds on the ideas previously pondered by nous, and provides a subcrate under ./cognos for easy parsing. Thank you Atagen for letting me play with the idea.

License

This project is made available under Mozilla Public License (MPL) version 2.0. See LICENSE for more details on the exact conditions. An online copy is provided here.