comparison.md

Feature comparison with Ninja

n2 is intended to be able to build any project that Ninja can load. Here is a comparison of things n2 does worse and better than Ninja.

Improvements

Here are some things n2 improves over Ninja:

• Builds are more incremental: n2 starts running tasks as soon as an out of date one is found, rather than gathering all the out of date tasks before executing as Ninja does.
• Fancier status output, modeled after Bazel. Here's a small demo.
• -d trace generates a performance trace that can be visualized by Chrome's about:tracing or alternatives (speedscope, perfetto).

Missing

• Windows is incomplete.
  • Ninja has special handling of backslashed paths that n2 doesn't yet follow.
• Dynamic dependencies.
• console pool. n2 currently just treats console as an ordinary pool of depth 1, and only shows console output after the task completes. In practice this means commands that print progress when run currently show nothing until they're complete.
• subninja is only partially implemented.

Missing flags

• -l, load average throttling
• -n, dry run

Missing subcommands

Most of -d (debugging), -t (tools).

No -w (warnings).