ng build --watch --preserve-symlinks dies with EMFILE when watch mode starts #34184

Hi team,

We have one monorepo. A web app and an API both compile a shared model folder. That folder has no package.json. The web app reaches it through a symlink, libs/model, pointing at ../../model next to the web app. The watch command is ng build --watch --preserve-symlinks. We need preserveSymlinks so that link keeps working. On 22.1.7 this watch runs fine.

After moving @angular/cli and @angular/build to 22.2.0, the bundle still completes (about 92 seconds). Then the process dies as soon as watch mode starts:

Watch mode enabled. Watching for file changes...

Error: EMFILE: too many open files, watch
    at FSWatcher._handle.onchange (node:internal/fs/watchers:267:21)

The stack goes through chokidar. We're on macOS, Node 24.16.0. ulimit -n 65536 does not stop it.

22.2 uses chokidar for this case so a directory symlink is still rebuilt. That part is what #34060 fixed for #34039, and the rebuilds do show up. The new problem is everything else the watcher opens. In setupWatcher, **/node_modules/** is only added to the ignore list when preserveSymlinks is false. The comment says that is so npm link keeps working. With the flag on, chokidar calls fs.watch for every directory under node_modules. Ours is large enough that the process runs out of file handles.

This symlink is not an npm link, and it is not inside node_modules. Ignoring node_modules would still follow libs/model to the shared model folder. Could the watcher skip node_modules when preserveSymlinks is on, and only watch a package that was actually created with npm link?

We've gone back to 22.1.7 for now.