Catching all unhandled errors in Gulp

Question

Our Gulp build process fails for some new developers like this:

events.js:85
      throw er; // Unhandled 'error' event
            ^
Error: EMFILE, open '[some filename]'
    at Error (native)

The solution is to run:

ulimit -n 2048

So I'd like to catch the EMFILE error and replace it with a friendlier message. However, even wrapping the entire gulpfile.js in a try/catch doesn't seem to contain it.

Answer 1

It turns out that wrapping try/catch around everything doesn't work because the errors happen after (all) the code is executed. Injecting an error handler into every single pipe works:

function onError(e) {
    if (e.code === 'EMFILE') {
        console.error('Too many open files. You should run this command:\n    ulimit -n 2048');
        process.exit(1);
    }
    gutil.log(e.message);
    process.exit(1);
}

...
var result = bundler.bundle();

result = result
    .on('error', onError)
    .pipe(source(name))
    .pipe(buffer());