motivation

this rust project 'logone' implements a rust program and crate library to consume the nix output produced by:

`nix build --log-format internal-json`

and attempts to make nix logging less verbose / nosiy to be used in the nix backend of cargo.

level

how it works, depends on the selected log level using --level.

verbose

• when building several drv(s) in parallel, it accumulate the individual logs and outputs them in complete sequences

errors

• it only prints the outputs of builds which have failed
• it prevents the print of the nix error summary (DRY)

cargo

this mode imitates the cargo build style of logging i.e.:

• only log start of crate builds
• only log warnings / errors
• be very concise / precise, don't add the compiler call

project status

• prototype as standalone binary works
  • support for @nix
• minimalist logging
  • support for custom extensions like @cargo
  • add 3 log levels: --level cargo|errors|verbose
    • "cargo" (default): ignores logs from @nix and uses @cargo logs and error detection
    • "errors" only use @nix logs, ignore @cargo messages for the failing build
    • "verbose" shows all @nix messages for each build: successful and failed ones but still in sorted blocks (no mixed logging), ignores all @cargo messages
  • remove --timing / --min-time / --debug
  • print the @cargo internal logs properly & use the exit code
• make it a crate libary

a good illustration on how to @nix protocol works and can be implemented. it sometimes shows different results than nix-output-monitor and nix itself:

• https://github.com/nixos/nix/issues/13909
• https://github.com/nixos/nix/issues/13910
• https://github.com/nixos/nix/issues/13935

examples

as an example there are outputs in the tests folder one can experiment with:

the 'verbose' level:

cat tests/example.stdin2 | cargo run -- --json --level verbose

the 'cargo' level:

cat tests/example.stdin11 | cargo run -- --json --level cargo
cat tests/example.stdin12 | cargo run -- --json --level cargo

the 'errors' level:

cat tests/example.stdin2 | cargo run -- --json --level errors

license

logone is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT for details.