ng build output truncated when run as a child process

[imhoffd]

The output of ng build is truncated to 8192 bytes when run as a child process.

Versions

Angular CLI: 6.0.1
Node: 8.10.0
OS: darwin x64
Angular: 6.0.2
... common, compiler, compiler-cli, core, forms, http
... language-service, platform-browser, platform-browser-dynamic
... router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.6.0
@angular-devkit/build-angular     0.6.0
@angular-devkit/build-optimizer   0.6.0
@angular-devkit/core              0.6.0
@angular-devkit/schematics        0.6.0
@angular/cli                      6.0.1
@ngtools/webpack                  6.0.0
@schematics/angular               0.6.0
@schematics/update                0.6.1
rxjs                              6.1.0
typescript                        2.7.2
webpack                           4.6.0

Repro steps

• git clone https://github.com/dwieeb/ng-build-truncated-output
• npm install
• node script.js

Observed behavior

Desired behavior



Mention any other details that might be useful (optional)

Something I observed is that using setBlocking(true) in the ng bin file appears to flush the output properly:

#!/usr/bin/env node
'use strict';

process.stdout._handle.setBlocking(true);
process.stderr._handle.setBlocking(true);

// Provide a title to the process in `ps`.
// Due to an obscure Mac bug, do not start this title with any symbol.
process.title = 'ng';

var version = process.version.substr(1).split('.');
if (Number(version[0]) < 8 || (Number(version[0]) === 8 && Number(version[1]) < 9)) {
  process.stderr.write(
    'You are running version ' + process.version + ' of Node.js, which is not supported by Angular CLI v6.\n' +
    'The official Node.js version that is supported is 8.9 and greater.\n\n' +
    'Please visit https://nodejs.org/en/ to find instructions on how to update Node.js.\n'
  );

  process.exit(3);
}

require('../lib/init');

Could be related to stdout not being flushed before a process.exit() is called.

[filipesilva]

This is an interesting problem. For reference the issues on node seem to be nodejs/node#2360 and nodejs/node#19218.

A specially relevant highlight is nodejs/node#19218 (comment):

And the root cause identified as the fact that console.log non blocking, so if a process issues it and exits afterwards, the actual number of bytes written depends on the time gap between the two actions and the capability of the I/O channel to transfer the data in between the gap.

This makes me think that we shouldn't use console.log across our loggers and use process.stdout.write instead.

[imhoffd]

@filipesilva Would you accept a PR where the loggers are switched to using process.stdout.write?

[filipesilva]

@dwieeb I think we already do now in CLI 7.

Our webpack build uses a provided logger:

angular-cli/packages/angular_devkit/build_angular/src/browser/index.ts

Lines 189 to 205 in e5aea19

	export const getBrowserLoggingCb = (verbose: boolean): LoggingCallback =>
	(stats, config, logger) => {
	// config.stats contains our own stats settings, added during buildWebpackConfig().
	const json = stats.toJson(config.stats);
	if (verbose) {
	logger.info(stats.toString(config.stats));
	} else {
	logger.info(statsToString(json, config.stats));
	}
	if (stats.hasWarnings()) {
	logger.warn(statsWarningsToString(json, config.stats));
	}
	if (stats.hasErrors()) {
	logger.error(statsErrorsToString(json, config.stats));
	}
	};

The logger is instantiated in the CLI:

angular-cli/packages/angular/cli/lib/cli/index.ts

Line 16 in e5aea19

const logger = createConsoleLogger();

And will use process.stdout and process.stderr:

angular-cli/packages/angular_devkit/core/node/cli-logger.ts

Lines 18 to 22 in e5aea19

	export function createConsoleLogger(
	verbose = false,
	stdout: ProcessOutput = process.stdout,
	stderr: ProcessOutput = process.stderr,
	): logging.Logger {

[imhoffd]

Interesting, I'm still seeing this with latest CLI.

Angular CLI: 7.0.6
Node: 10.12.0
OS: darwin x64
Angular: 7.0.4
... common, compiler, compiler-cli, core, forms, http
... language-service, platform-browser, platform-browser-dynamic
... router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.10.6
@angular-devkit/build-angular     0.10.6
@angular-devkit/build-optimizer   0.10.6
@angular-devkit/build-webpack     0.10.6
@angular-devkit/core              7.0.6
@angular-devkit/schematics        7.0.6
@angular/cli                      7.0.6
@ngtools/webpack                  7.0.6
@schematics/angular               7.0.6
@schematics/update                0.10.6
rxjs                              6.3.3
typescript                        3.1.6
webpack                           4.19.1

The following trick still works:

process.stdout._handle.setBlocking(true);
process.stderr._handle.setBlocking(true);

I can investigate further next week.

[alan-agius4]

Hi @dwieeb, is this still a problem?

[imhoffd]

No, I haven't seen this in a while.

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