Passing in V8 flags to a node process that executes ng build/serve throws

[jackofdiamond5]

Command

build

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

18.2.12

Description

I am firing a nodejs process that executes the ng build schematic.
For example, it looks something like this - node --max-old-space-size=4096 node_modules/@angular/cli/bin/ng build. This throws because of the --max-old-space-size V8 flag that I pass in to node.

I traced the problem to this PR#28758 which uses process.execArgv and passes them in as execArgv to the options of the newly-created worker. Later on piscina will spawn a worker with the provided options, without doing any filtering, but I figured this is the intended behavior on their part.

According to nodejs when spawning worker threads, we cannot pass in any V8 flags (ref). Also, there's an open issue nodejs/node#41103 to make worker threads stop throwing errors for unsupported options but until that is resolved my best guess is that if process.execArgv is to be used, then some sort of filtering should be applied on these options before passing them in to the worker's constructor.

Minimal Reproduction

1, Create a new application with @angular/cli@19.
2. Navigate to the newly-created project's root.
3. Run node --max-old-space-size=4096 node_modules/@angular/cli/bin/ng build

Exception or Error

✘ [ERROR] Initiated Worker with invalid execArgv flags: --max-old-space-size=4096 [plugin angular-compiler]
 node_modules/piscina/dist/index.js:130:23:
      130 │         const worker = new node_worker_threads_1.Worker((0, node_...

Your Environment

Angular CLI: 19.0.0
Node: 20.17.0
Package Manager: npm 10.8.2
OS: win32 x64

Angular:
...

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.1900.0 (cli-only)
@angular-devkit/core         19.0.0 (cli-only)
@angular-devkit/schematics   19.0.0 (cli-only)
@schematics/angular          19.0.0 (cli-only)

Anything else relevant?

No response

[clydin]

Thank you for the report. This is something the team will be investigating.

For max-old-space-size specifically, you may not need to use that option anymore with the Angular CLI. Newer Node.js versions have improved their memory initialization process significantly over previous versions.

[jackofdiamond5]

For max-old-space-size specifically, you may not need to use that option anymore with the Angular CLI. Newer Node.js versions have improved their memory initialization process significantly over previous versions.

@clydin Yeah you're right, I don't need the max-old-space-size anymore, I used it as a mere example to illustrate a V8 option that would cause an error when used like that.

One exception is with ng lint where we have a huge application and currently, in order to lint it, we use that flag, otherwise it runs out of memory. But without going through the code I'm going to guess that the ng lint does not spawn any workers and that's why it doesn't throw like ng serve/build do.

[viceice]

I've this problem with --use-openssl-ca

[adzhiljano]

For max-old-space-size specifically, you may not need to use that option anymore with the Angular CLI. Newer Node.js versions have improved their memory initialization process significantly over previous versions.

Unfortunately, max-old-space-size is our only option right now. On a fairly large app, we're currently getting the following (without passing any flags):

X [ERROR] Angular compilation initialization failed. [plugin angular-compiler]

  Error [ERR_WORKER_OUT_OF_MEMORY]: Worker terminated due to reaching memory limit: JS heap out of memory
      at [kOnExit] (node:internal/worker:313:26)
      at Worker.<computed>.onexit (node:internal/worker:229:20)

We've also seen the following, that seems to happen randomly:

X [ERROR] The expression evaluated to a falsy value:

  (0, node_assert_1.default)(compilation)
 [plugin angular-compiler]

  This error came from the "onStart" callback registered here:

    node_modules/@angular/build/src/tools/esbuild/angular/compiler-plugin.js:107:18:
      107 │             build.onStart(async () => {
          ╵                   ~~~~~~~

    at setup (...\node_modules\@angular\build\src\tools\esbuild\angular\compiler-plugin.js:107:19)
    at async handlePlugins (...\node_modules\esbuild\lib\main.js:1194:20) 

Saw that PR #29118 by @alan-agius4 is Closed, can you please give us an update?
Thanks!

[janpapenbrock]

Just ran into this after upgrading to Angular 19, too, and found the following workaround, maybe it helps someone.

Does not work:
node --max_old_space_size=6000 ./node_modules/@angular/cli/bin/ng build

Does work:
NODE_OPTIONS="--max-old-space-size=6000" node ./node_modules/@angular/cli/bin/ng build

(Validated via: NODE_OPTIONS="--max-old-space-size=6000" node -e 'console.log(v8.getHeapStatistics().heap_size_limit)', tested on Node v22.11.0)

[alan-agius4]

Thanks for reporting this issue. Luckily, it has already been fixed in one of the recent releases. Please update to the most recent version to resolve the problem.

If the problem persists in your application after upgrading, please open a new issue, provide a simple repository reproducing the problem, and describe the difference between the expected and current behavior. You can use ng new repro-app to create a new project where you reproduce the problem.