Memory leack in concurent build proccess.

[syonfox]

Hi, i have been using this and just restarting in my dev proccess ;) but am trying to track down why my concurrent bundling is leaky. to tighten up the whole process. Does anyone have insight into this problem. I am watching many code files for different bundles

Running "concurrent:bundle" (concurrent) task
Verifying property concurrent.bundle exists in config...OK
Files: [no src] -> bundle
Options: limit=16, indent, logConcurrentOutput
>> Warning: There are more tasks than your concurrency limit. After this limit
>> is reached no further tasks will be run until the current tasks are
>> completed. You can adjust the limit in the concurrent task options
(node:22429) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [WriteStream]. Use emitter.setMaxListeners() to increase limit
    at _addListener (node:events:587:17)
    at WriteStream.prependListener (node:events:619:14)
    at prependListener (/home/mango/git/plan-webmap/node_modules/readable-stream/lib/_stream_readable.js:92:69)
    at Pumpify.Readable.pipe (/home/mango/git/plan-webmap/node_modules/readable-stream/lib/_stream_readable.js:644:3)
    at /home/mango/git/plan-webmap/node_modules/grunt-concurrent/tasks/concurrent.js:70:15
    at /home/mango/git/plan-webmap/node_modules/grunt-concurrent/node_modules/async/dist/async.js:2588:44
    at replenish (/home/mango/git/plan-webmap/node_modules/grunt-concurrent/node_modules/async/dist/async.js:446:21)
    at /home/mango/git/plan-webmap/node_modules/grunt-concurrent/node_modules/async/dist/async.js:451:13
    at Object.eachLimit$1 (/home/mango/git/plan-webmap/node_modules/grunt-concurrent/node_modules/async/dist/async.js:2718:34)
    at Object.awaitable (/home/mango/git/plan-webmap/node_modules/grunt-concurrent/node_modules/async/dist/async.js:211:32)
    at Object.<anonymous> (/home/mango/git/plan-webmap/node_modules/grunt-concurrent/tasks/concurrent.js:38:9)
    at Object.<anonymous> (/home/mango/git/plan-webmap/node_modules/grunt/lib/grunt/task.js:252:15)
    at Object.thisTask.fn (/home/mango/git/plan-webmap/node_modules/grunt/lib/grunt/task.js:70:16)
    at Object.<anonymous> (/home/mango/git/plan-webmap/node_modules/grunt/lib/util/task.js:294:30)
    at Task.runTaskFn (/home/mango/git/plan-webmap/node_modules/grunt/lib/util/task.js:244:24)
    at Task.<anonymous> (/home/mango/git/plan-webmap/node_modules/grunt/lib/util/task.js:293:12)
    at /home/mango/git/plan-webmap/node_modules/grunt/lib/util/task.js:220:11
    at processTicksAndRejections (node:internal/process/task_queues:78:11)
(node:22429) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [WriteStream]. Use emitter.setMaxListeners() to increase limit

Looking into this it might be related to https://github.com/node-fetch/node-fetch/issues/1295#issuecomment-921178548

//line 38
        async.eachLimit(tasks, options.limit, (task, next) => {
            const subprocess = grunt.util.spawn({
                grunt: true,
                args: arrify(task).concat(flags),
                opts: {
                    stdio: [
                        'ignore',
                        'pipe',
                        'pipe'
                    ]
                }
            }, (error, result) => {
                if (!options.logConcurrentOutput) {
                    let output = result.stdout + result.stderr;
                    if (options.indent) {
                        output = indentString(output, 4);
                    }

                    grunt.log.writeln(`\n${output}`);
                }

                next(error);
            });

            if (options.logConcurrentOutput) {
                let subStdout = subprocess.stdout;
                let subStderr = subprocess.stderr;
                if (options.indent) {
                    subStdout = subStdout.pipe(padStream(4));
                    subStderr = subStderr.pipe(padStream(4));
                }

                subStdout.pipe(process.stdout);
                subStderr.pipe(process.stderr);
            }

            subprocesses.push(subprocess);
        }, error => {

//...
            if (options.logConcurrentOutput) {
                let subStdout = subprocess.stdout;
                let subStderr = subprocess.stderr;
                if (options.indent) {
                    subStdout = subStdout.pipe(padStream(4));
                    subStderr = subStderr.pipe(padStream(4));
                }
//line 70
                subStdout.pipe(process.stdout);
                subStderr.pipe(process.stderr);
            }

Will keep poking around but it seems over time my project crashes. not sure exactly where the leak is this is just one lead.

[syonfox]

Ok so I think I fixed this with the fallowing simit added around line 40

if(tasks.length > 10) {
                    let newListenerLimit = tasks.length + 10; // do we need 10 more maybe not but maybe oher things are using the normal 10 limit
                    grunt.log.oklns(
                        'Warning: There are more tasks than your event listener limit. Incresing this to '+ newListenerLimit
                        + "// process.stdout.setMaxListeners(newListenerLimit);"
                    );
                    process.stdout.setMaxListeners(newListenerLimit);
                    process.stderr.setMaxListeners(newListenerLimit);
                }
//just above async.eachLimit(tasks, options.limit, (task, next) => {