Build report, console modes, and warning control by gnodet · Pull Request #12572 · apache/maven

gnodet · 2026-07-28T18:28:27Z

This PR has been superseded. The work has been split into 5 smaller, independently reviewable PRs that form a dependency chain. Each builds on the previous one.

PR Chain

#	PR	Title	Base
1	#12694	Logging foundation: structured LogEvent, JUL handler, Log API enhancements	`master`
2	#12695	Build report: structured JSON report with per-mojo log capture	`feature/logging-foundation`
3	#12697	Console modes: `--console=plain/rich/verbose/machine`	`feature/build-report`
4	#12698	Warning mode, diagnostic collector, BuilderProblem enrichments	`feature/console-modes`
5	#12699	mvnlog: build log viewer, integration tests, script routing	`feature/warning-mode`

Follow-up: #12647 — Pipe structured BuilderProblems into DiagnosticCollector (targets feature/warning-mode)

Review starts at PR 1 and proceeds through the chain. Each PR compiles and passes tests independently.

The rest of this description is kept as a high-level overview of the full feature set across all 5 PRs.

Build Report Foundation

What users see

`--console=plain` — compact CI output (default when `CI=true`)

One line per completed module, no ANSI, no status bar. Auto-selected on CI (CI=true, JENKINS_URL, etc.):

$ mvn validate --console=plain
[INFO] Apache Maven [1/38] ................................ SUCCESS [  0.539 s]
[INFO] Maven 4 API [2/38] ................................. SUCCESS [  0.017 s]
[INFO] Maven 4 API :: Meta annotations [3/38] ............. SUCCESS [  0.019 s]
[INFO] Maven 4 API :: Dependency Injection [4/38] ......... SUCCESS [  0.018 s]
[INFO] Maven 4 API :: XML [5/38] .......................... SUCCESS [  0.027 s]
[INFO] Maven 4 API :: Model [6/38] ........................ SUCCESS [  0.070 s]
...
[INFO] Maven 4 CLI [35/38] ................................ SUCCESS [  0.240 s]
[INFO] Maven Plugin Testing Mechanism [36/38] ............. SUCCESS [  0.162 s]
[INFO] Maven Embedder (deprecated) [37/38] ................ SUCCESS [  0.178 s]
[INFO] Apache Maven Distribution [38/38] .................. SUCCESS [  0.514 s]
[INFO]
[INFO] BUILD SUCCESS
[INFO] 38 modules | 38 passed
[INFO] Total time:  5.519 s
[INFO] Full report: target/build-reports/build-report-latest.json

`--console=rich` — live status bar (default on interactive TTY)

During the build, the bottom of the terminal shows a live JLine status area that updates in place. All plugin INFO/WARN output is suppressed — only ERRORs scroll above the status bar:

 Maven 4.1.0-SNAPSHOT ─ building Apache Maven 4.1.0-SNAPSHOT
 ● maven-core  maven-compiler-plugin:compile  8s
 ● maven-api-core  maven-surefire-plugin:test  3s
────────────────────────────────────────────────────────────────────
 ✓ ✓ ✓ ● ● ○ ○ ○ ○ ○ [5/10]  32s  ↓ core-4.1.0.jar 256KB/512KB

With large reactors (where per-module indicators don't fit), the separator becomes a proportional progress bar:

 Maven 4.1.0-SNAPSHOT ─ building Apache Camel 4.22.0-SNAPSHOT
 ● camel-jaxb  flatten-maven-plugin:flatten  0s
 ● camel-core  maven-compiler-plugin:compile  8s
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━────────────────────────────────────── [77/673]  1m 18s

At the end, the status bar is torn down and replaced with a compact summary:

BUILD SUCCESS
38 modules | 38 passed
Total time:  5.772 s
Full report: target/build-reports/build-report-latest.json

When diagnostics are present:

BUILD SUCCESS
38 modules | 38 passed
Diagnostics: 3 warnings — run mvnlog to see details
Total time:  32.1s
Full report: target/build-reports/build-report-latest.json

`--console=machine` — JSON lines for tools and LLM agents

One JSON object per line, designed for piping to jq, IDE integrations, and AI agents:

$ mvn validate --console=machine
{"event":"build.started","timestamp":"...","projectCount":38,"goals":"validate","profiles":"signing-key"}
{"event":"module.started","timestamp":"...","module":"Apache Maven","groupId":"org.apache.maven","artifactId":"maven","version":"4.1.0-SNAPSHOT","index":1,"total":38}
{"event":"mojo.started","timestamp":"...","module":"Apache Maven","plugin":"maven-enforcer-plugin","goal":"enforce","phase":"validate","executionId":"enforce-bytecode-version"}
{"event":"log","timestamp":"...","level":"INFO","module":"maven","logger":"...","message":"Rule 0: org.apache.maven.enforcer.rules.version.RequireJavaVersion passed"}
{"event":"mojo.succeeded","timestamp":"...","module":"Apache Maven","plugin":"maven-enforcer-plugin","goal":"enforce","duration":0.33}
{"event":"module.succeeded","timestamp":"...","module":"Apache Maven","duration":0.543}
...
{"event":"build.finished","timestamp":"...","status":"SUCCESS","duration":4.363,"total":38,"passed":38,"failed":0,"skipped":0}

`--console=verbose` — full output (Maven 4.0 default)

Unchanged from today's Maven 4.0 behavior — all per-mojo banners, plugin output, download progress.

`--console=auto` (the default)

Selects automatically: CI=true or JENKINS_URL set → plain; interactive TTY → rich; otherwise → verbose.

Warning summary at end of build

All console modes show a deduplicated warning summary at end of build (unless --warning-mode=none).

--warning-mode controls behavior:

Mode	During build	End of build	Exit code
`all` (default)	show warnings	show summary	0
`summary`	suppress inline	show summary	0
`none`	suppress all	suppress all	0
`fail`	show warnings	show summary	1 (if any warning)

Version info on failure

When the build fails, Maven and Java version are printed to help with bug reports.

Structured build report JSON

Every build writes target/build-reports/build-report-latest.json with per-module, per-mojo execution data, log output, and diagnostics.

`mvnlog` — build report viewer

After a build completes, mvnlog reads the report JSON and renders a human-readable view:

$ mvnlog                    # view latest build report
$ mvnlog warnings           # just the deduplicated warnings
$ mvnlog module core        # output from a specific module
$ mvnlog --json             # raw JSON output for tools

How it works

Console mode architecture

Each console mode is a pair of cooperating classes:

Mode	`BuildEventListener`	`ExecutionListener`
`rich`	`RichBuildEventListener` (JLine status bar)	`RichExecutionEventLogger` (suppress per-mojo banners)
`plain`	`PlainBuildEventListener` (no-op status)	`PlainExecutionEventLogger` (one line per module)
`machine`	`MachineBuildEventListener` (JSON log/transfer events)	`MachineExecutionEventLogger` (JSON lifecycle events)
`verbose`	existing `SimpleBuildEventListener`	existing `ExecutionEventLogger`

Build report pipeline

BuildReportCollector — injected ExecutionListener that captures every lifecycle event, mojo execution, and log message into an in-memory report
BuildReportWriter — writes the report to target/build-reports/build-report-latest.json at session end
BuilderProblem — universal diagnostic currency: model validation warnings, plugin validation, and (with PR Fix #12643: Pipe structured BuilderProblems into DiagnosticCollector #12647) plugin-reported diagnostics all flow through BuilderProblem into DiagnosticCollector

DiagnosticReporter (PR #12647)

A new Maven 4 API service that plugins can inject to report structured diagnostics:

BuilderProblem objects with severity, key, source location, suggestion, and documentation URL
Per-location dedup keys prevent duplicate warnings from incremental builds
Implemented in maven-compiler-plugin (PR Report structured BuilderProblems from compiler diagnostics maven-compiler-plugin#1101)

…s, warning control Add a comprehensive build reporting infrastructure to Maven 4.1.0: **Structured Build Report** (Phase 0-1) - BuildReport API in maven-api-core with ModuleReport, MojoReport, FailureReport, and LogEvent data model - BuildReportCollector EventSpy that captures lifecycle events, per-mojo log output, and build diagnostics - JSON writer producing timestamped build-report-*.json files - Deduplicated warning summary printed at end of build **Console Modes** (Phase 2-4) - ConsoleMode enum (AUTO/PLAIN/RICH/MACHINE) with --console CLI flag - PlainBuildEventListener for compact CI output - RichBuildEventListener with JLine status bar for interactive terminals - MachineBuildEventListener for JSON-lines structured output **Warning Control** (Phase 5) - --warning-mode CLI flag (ALL/SUMMARY/NONE) - Log.warn() interception for automatic Maven 3 plugin coverage - -Dmaven.diagnostic.suppress=key for selective suppression **Build Log Viewer** (mvnlog) - mvnlog CLI tool for post-build report inspection - --json flag for raw JSON output - Shell scripts for Unix and Windows **Plugin API** (DiagnosticReporter) - BuilderProblem.builder() static factory with fluent Builder API - DiagnosticReporter Service interface for Maven 4 plugins - DefaultDiagnosticReporter implementation with auto-discovery Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Port and modernize the incremental build context from PR #1118, building on the original Sonatype plexus-build-api / Takari incrementalbuild work. API (maven-api-core): - BuildContext: register inputs, check status, associate outputs, skip execution, automatic stale output cleanup - SPI: Workspace (NORMAL/ESCALATED/SUPPRESSED), CommittableBuildContext, BuildContextEnvironment, BuildContextFinalizer - Diagnostic messages are NOT part of this API — use DiagnosticReporter from the build report API instead Implementation (maven-impl): - DefaultBuildContext with timestamp/size change detection - State serialization for cross-build persistence - PathMatcherFactory integration for Ant-style patterns - 36 tests Maven integration (maven-core): - MojoExecutionScoped DI wiring - ClasspathDigester + MojoConfigurationDigester for automatic configuration change detection - MavenBuildContextFinalizer for post-mojo commit - maven.buildcontext.skip property to disable entirely - Performance: released-artifact digest bypass, no-op state skip, single-syscall file status, field reflection cache Based on #12572 (Build Report Foundation). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

When the reactor has more modules than fit as individual ✓/●/○ indicators on the terminal width, switch to a full-width proportional progress bar: green ━ for completed, yellow ━ for active, dim ─ for remaining, with the counter and elapsed time appended. The progress bar replaces the separator line — one line instead of two (no redundant horizontal rule above the bar). This also gives an extra project slot line to the status area. Small reactors (≤ maxIndicators) keep the per-module indicators with the separate separator line, where each module gets its own symbol. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…ollector Route structured validation problems from 4 pathways (settings, toolchains, model validation, graph building) into DefaultDiagnosticCollector so they appear in the build report with full key/suggestion/documentationUrl metadata instead of being re-logged as plain text. Pathways: - LookupInvoker: settings validation problems - MavenInvoker: toolchains validation problems - DefaultProjectsSelector: model validation problems (ModelProblem → BuilderProblem) - DefaultMaven: graph building problems (ModelProblem → BuilderProblem) Also adds EXCLUDED_LOGGERS in BuildReportCollector to prevent double-counting when the same problems are both piped structurally and logged via SLF4J. Migrates all test files from DefaultBuilderProblem constructor to BuilderProblem.builder() API. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Change the PluginValidationManager interface from String-based to BuilderProblem-based, enabling structured problem reporting with keys, severity, and suggestions throughout the plugin validation pipeline. - Change 3 abstract report methods from String issue to BuilderProblem - Add deprecated String-based default methods for backward compat - Update all 9 call sites (7 validators + 1 plugin manager) to create BuilderProblem with structured key, severity, and suggestion - Inject DefaultDiagnosticCollector into DefaultPluginValidationManager to pipe problems into the diagnostic pipeline - Add japicmp exclusion for the intentional API break - Add DefaultPluginValidationManager to EXCLUDED_LOGGERS in BuildReportCollector to prevent double-counting Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

@nAmed

- Injector.bindFactory(Class, Function<Key, T>): factory-based binding that receives the full injection-point Key (including @nAmed qualifier), enabling qualifier-derived instances like hierarchical logger names. - Log.child(String): returns a child logger with hierarchical naming (e.g. "compiler:compile" → "compiler:compile.diagnostics"), useful when plugins delegate to sub-components that need independently filterable log output. - Log.problem(BuilderProblem): reports a structured problem to the diagnostic collector with dedup key, suggestion, and documentation URL, while also logging at the appropriate level. Uses a thread-local flag to prevent double-counting by BuildReportCollector's WARN auto-promotion. - DefaultMavenPluginManager: switched from bindInstance to bindFactory for Log injection, so @Inject @nAmed("diagnostics") Log in a DI-managed plugin component gets "compiler:compile.diagnostics". - Fixed pre-existing bug: DefaultLog.warn(Supplier, Throwable) was calling logger.info() instead of logger.warn(). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…factory" This reverts commit 3f3565c.

… bindFactory() Keep only Log.child(String) — a clean, backward-compatible default method that lets sub-components log under an independently filterable name (e.g. "compiler:compile" → "compiler:compile.diagnostics"). Removed from the earlier commit: - Log.problem(BuilderProblem) — conflated logging with problem reporting; plugins should use DiagnosticReporter directly instead. - Injector.bindFactory() — too much DI machinery for a single use case; plugins can call logger.child() at the call site. - STRUCTURED_PROBLEM_ACTIVE ThreadLocal — fragile invisible coupling between DefaultLog and BuildReportCollector. - Factory-based Log binding in DefaultMavenPluginManager. Also fixes pre-existing bug: DefaultLog.warn(Supplier, Throwable) was calling logger.info() instead of logger.warn(). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

LogEvent now carries projectId() and mojoId() so every log message (including JUL-bridged ones) is self-describing. The mojo ID is set in MDC by LoggingExecutionListener on mojo start/finish, read by ProjectBuildLogAppender, and embedded in the event. Machine mode emits the mojoId in its JSON output. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

DefaultLog now uses the mojo implementation class name as its SLF4J logger name instead of getFullGoalName(). This makes Log and JUL produce identical SLF4J loggers when plugins use the conventional class-name pattern, and enables hierarchical SLF4J level configuration (e.g. org.apache.maven.plugin.compiler=DEBUG). The mojoId format changes from goal@executionId to prefix:goal@executionId (e.g. compiler:compile@default-compile) for unambiguous identification. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Debug is currently overloaded: user-relevant diagnostic messages (e.g. "recompiling because annotation processor changed") share the same level as Maven internal details (resolver negotiation, model interpolation). This makes -X output unusable for users investigating their build. Add trace() methods to the Maven 4 Log API, mirroring the existing debug/info/warn/error pattern. Trace maps to SLF4J TRACE and JUL FINEST. The intent is that Maven internals demote to trace, leaving debug for user-facing diagnostic information. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dismiss review because of confusion. Was targeting the addition of trace log event, did not realize that it was part of a larger work.

gnodet · 2026-08-07T22:11:45Z

Closing — this monolith PR has been fully superseded by the 5-PR chain:

Logging foundation: structured LogEvent, JUL handler, Log API enhancements #12694 — Logging foundation
Build report: structured JSON report with per-mojo log capture #12695 — Build report
Console modes: --console=plain/rich/verbose/machine #12697 — Console modes
Warning mode, diagnostic collector, BuilderProblem enrichments #12698 — Warning mode + diagnostics
mvnlog: build log viewer, integration tests, script routing #12699 — mvnlog viewer

Plus #12647 — Structured BuilderProblems pipeline

Review starts at PR #12694.

Add a structured build report that captures per-module and per-mojo execution results, timing, log events, and failures as a JSON file (target/build-reports/) at the end of every build. Part 2 of the #12572 split. Builds on the logging foundation from PR #12694 (LogEvent, LogLevel, LogEventSink). New API interfaces: - BuildReport: root report with metadata, modules, failures, problems - BuildStatus: SUCCESS/FAILURE/SKIPPED enum - ModuleReport: per-module results with mojo list - MojoReport: per-mojo execution with captured log events - FailureReport: exception details and stack traces Implementation: - BuildReportCollector: EventSpy that tracks lifecycle events and captures log output via LogEventSink, routing events to mojo/module/build-level buffers using thread-based tracking - BuildReportJsonWriter: zero-dependency JSON serializer - Atomic file writes with timestamped files and latest symlink - Thread-safe for parallel builds (-T) Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add the --console CLI flag with four output modes: - plain: compact one-line-per-module output for CI - rich: JLine status bar with live reactor progress - verbose: full mojo-level output (current default) - machine: JSON lines for piping to external tools Part 3 of the #12572 split (depends on build report PR #12695). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add --warning-mode CLI flag (summary/all/none/fail) for controlling how build warnings are displayed. Enrich BuilderProblem with key, suggestion, documentationUrl, INFO severity, and a builder API. Add DiagnosticReporter service and DefaultDiagnosticCollector for deduplication across parallel module builds. Part 4 of the #12572 split (depends on console modes PR #12697). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add the mvnlog tool for viewing and analyzing build-report JSON files. Includes BuildReportRenderer for human-readable output, SimpleJsonReader for dependency-free JSON parsing, shell scripts (mvnlog/mvnlog.cmd), and --log routing in mvn/mvn.cmd. Also adds integration tests for build report generation, console modes, and the mvnlog viewer, plus --console=verbose flags for ITs that depend on verbose output. Part 5 of the #12572 split (depends on warning mode PR #12698). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gnodet mentioned this pull request Jul 28, 2026

Add incremental build context API and implementation #12576

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gnodet changed the title ~~Fix #12571: Add structured build report (Phase 0)~~ Fix #12571: Build output overhaul — structured report, console modes, warning control Jul 29, 2026

gnodet changed the title ~~Fix #12571: Build output overhaul — structured report, console modes, warning control~~ Fix #12571: Build Report Foundation — structured report, console modes, warning control Jul 29, 2026

gnodet force-pushed the feature/12571-build-report branch 6 times, most recently from 3192bb4 to 87be78e Compare July 29, 2026 14:59

gnodet mentioned this pull request Jul 29, 2026

[MNG-6899] Maven Runtime Metrics System #8417

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gnodet changed the title ~~Fix #12571: Build Report Foundation — structured report, console modes, warning control~~ Build Report Foundation — structured report, console modes, warning control Jul 29, 2026

gnodet added this to the 4.1.0 milestone Jul 30, 2026

gnodet force-pushed the feature/12571-build-report branch from d7bb105 to 63da8ce Compare July 31, 2026 11:57

This was referenced Jul 31, 2026

Fix #12643: Pipe structured BuilderProblems into DiagnosticCollector #12647

Closed

Report structured BuilderProblems from compiler diagnostics apache/maven-compiler-plugin#1101

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gnodet force-pushed the feature/12571-build-report branch from 83ce6ac to 6fd5983 Compare August 4, 2026 22:33

gnodet changed the title ~~Build Report Foundation — structured report, console modes, warning control~~ Build report, console modes, and warning control Aug 6, 2026

gnodet and others added 7 commits August 7, 2026 08:11

Revert "Add Log.child(), Log.problem(), and injection-point-aware DI …

a37fe39

…factory" This reverts commit 3f3565c.

gnodet mentioned this pull request Aug 7, 2026

Backport Log API enhancements and mojo MDC to 4.0.x #12690

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desruisseaux previously approved these changes Aug 7, 2026

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desruisseaux requested review from desruisseaux and removed request for desruisseaux August 7, 2026 09:58

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github-actions Bot removed this from the 4.1.0 milestone Aug 7, 2026

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PR Chain

Build Report Foundation

What users see

--console=plain — compact CI output (default when CI=true)

--console=rich — live status bar (default on interactive TTY)

--console=machine — JSON lines for tools and LLM agents

--console=verbose — full output (Maven 4.0 default)

--console=auto (the default)

Warning summary at end of build

Version info on failure

Structured build report JSON

mvnlog — build report viewer

How it works

Console mode architecture

Build report pipeline

DiagnosticReporter (PR #12647)

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`--console=plain` — compact CI output (default when `CI=true`)

`--console=rich` — live status bar (default on interactive TTY)

`--console=machine` — JSON lines for tools and LLM agents

`--console=verbose` — full output (Maven 4.0 default)

`--console=auto` (the default)

`mvnlog` — build report viewer