Console modes: --console=plain/rich/verbose/machine

[gnodet]

Summary

Part 3 of the logging feature chain. Depends on #12695 (build report).

Adds the --console CLI flag with four output modes:

• plain — compact one-line-per-module output, ideal for CI (auto-selected in CI environments)
• rich — JLine status bar with live reactor progress (auto-selected on interactive TTYs)
• verbose — full mojo-level output, current Maven 4.0 default behavior
• machine — JSON lines: one typed JSON object per lifecycle event, designed for piping to external tools

Auto-detection (--console=auto, the default): CI → plain, interactive TTY → rich, otherwise → verbose.

Files changed (16 files, ~4000 insertions)

Area	Files
API	Options.java (+console())
Event loggers	PlainExecutionEventLogger, RichBuildEventListener, RichExecutionEventLogger, MachineBuildEventListener, MachineExecutionEventLogger
CLI wiring	CommonsCliOptions, LayeredOptions, LookupInvoker (preliminary interactive detection), MavenInvoker (console mode switch + transfer listener)
Existing logger	ExecutionEventLogger (version info on failure)
Tests	5 test classes with full coverage

PR chain

#	PR	Feature
1	#12694	Logging foundation
2	#12695	Build report
3	This PR	Console modes
4	#12698	Warning mode + diagnostics
5	#12699	mvnlog viewer
6	#12702	Structured problems pipeline
7	#12714	TRACE level migration

Test plan

• mvn test -pl impl/maven-cli — all 692 tests pass
• mvn test -pl impl/maven-core — all tests pass
• CI validation

🤖 Generated with Claude Code

[gnodet]

One format worth considering for the machine-readable console mode: logfmt.

level=INFO  build=a1b2c3 module=my-app execution=maven-compiler-plugin:compile:default phase=compile ts=1234567890123 msg="Compiling 42 source files"
level=ERROR build=a1b2c3 module=my-app execution=maven-compiler-plugin:compile:default phase=compile ts=1234567890456 msg="Compilation failure"
level=INFO  build=a1b2c3 module=my-app execution=maven-compiler-plugin:compile:default result=FAILURE duration_ms=1823 msg="Mojo finished"

It sits nicely between plain text (human-readable) and JSON lines (fully structured): parseable by Loki, Vector, Grafana out of the box, but still legible with a plain cat.

The interesting property: with build + module + execution as grouping keys, the full hierarchy (modules → executions → log events + timing + results) can be reconstructed from the flat stream by any consumer.

Could be offered as a --console=logfmt option, or considered as the canonical machine format if we want to converge on a single representation.

[gnodet-bot]

Console modes review — overall this is solid. Three specific issues worth addressing before merge.

This review was generated by an AI agent, Hermès on behalf of @gnodet.

[gnodet-bot]

✖️ Bug: missing — silently collides in multi-module builds

The key is not unique when two modules in the same reactor share the same (different s). in overwrites the prior entry; the subsequent in / returns or the wrong start time — producing zero or negative durations in the JSON output with no error.

correctly includes :

Same fix needed at lines 211 and 293.

[gnodet-bot]

✖️ Behavioral regression: downgraded from ERROR to INFO level

The original used for the status line, producing . This PR changes it to , producing .

The ANSI coloring () still makes the text visually red in terminals, but any tool that scans the log stream by level — CI scripts using , Maven wrappers, IDE build output parsers, test frameworks — will silently miss the failure signal. The level and the color serve different consumers.

[gnodet-bot]

nit: with increment — use

is declared but incremented inside at line 155. provides visibility but not atomicity for compound read-modify-write; the block is what makes the increment correct. The modifier is redundant and misleading — it implies the field can be safely read-and-acted-upon outside the lock.

already uses for the same pattern. has the same issue (line 83):

Then in : , and in : — no block needed.