Visual build monitor for Nix that transforms cryptic build logs into a clean,
real-time dependency graph. Think of it as NOM, but written in Rust with a
focus on speed, configurability, and showing you exactly what Nix is doing with
your builds.
Built with a modular parser under ./cognos that handles the ATerm
and internal-json log formats from Nix.
Note
ROM is still under active development. Things may break, output formats may change, and bugs are to be expected. If you encounter any issues, please report them!
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.
$ 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. Each package in your closure appears as a node, with spinners and timers showing real-time progress. When a build finishes, you'll see a clear status with neat little glyphs.
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!
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.
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.
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.
