Note
This is a tool developed for internal use, not an official Antithesis product. That said, we thought it was cool enough to release, and we hope you can use it (or at least take some ideas from it)!
Fluke is a tracing-based Nix evaluation cacher, which tracks a given evaluation's impurities, then looks for changes to them upon subsequent evals (primarily by using Watchman).
The Nix expression at default.nix contains everything you need to install Fluke:
$ nix-build
[...]
$ ./result/bin/flukeFluke has two entrypoints: fluke and fluke-nix-build. The latter is a wrapper around the former, providing a nix-build-like interface for adapting existing usages of the Nix CLI.
- Currently, Fluke only supports evaluating attrsets. This will probably change in the future!
- Our impurity logging patch only supports Lix, therefore Fluke only supports evaluating using Lix.
Nix (and Lix) unfortunately don't give us information about all impurities used by an evaluation, so we do The Easy Thing and give Lix a way to emit structured impurity metadata.
The general idea behind Fluke was originally implemented by Dave Scherer.
