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

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:

• NixOS/nix#13909
• NixOS/nix#13910
• NixOS/nix#13935

message types

these messages are embedded in @nix messages and they have an id field already

type 0

usage: to indicate that a crate build inside a mkDerivation has started of type rustc or build-script-build

@cargo { 
    "type": 0, 
    "crate_name": "prettyplease",
}

type 1

usage: to send arbitraty text messages (unused)

@cargo { "type": 1, "crate_name": "prettyplease", "messages": [ "message 1", "message 2", ... ] }

type 2

usage: to indicate that a mkDerivation has finished compiling a crate of type rustc call counterpart: finishes a type 0 message

@cargo { 
    "type": 2, 
    "crate_name": "prettyplease",
    "rustc_exit_code": 1, 
    "rustc_messages": [ 
        { "rendered": "cargo:rerun-if-changed=build.rs\\n 1    \\u001b[31mcargo:VERSION=0.2.37\\u001b[0m\\nError: \\\"Command: 'VERSION' on line: '4' not implemented yet!\\\"\\n\", 
          ...
        }
    ]
}

type 3

usage: to indicate a mkDerivation has finished compiling a crate counterpart: finishes a type 0 message

@cargo {
    "type": 3, 
    "crate_name": "prettyplease",
    "exit_code": 0, 
    "messages": [ "message 1", "message 2", ... ]
}

usage

nix build --log-format internal-json 2>&1 | logone --json --level cargo

or

nix build --log-format internal-json 2> >(logone --json --level cargo)

examples

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

the 'verbose' level:

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

the 'cargo' level:

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

the 'errors' level:

cat example/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.