Concurrent only runs first task on node v0.10.20

[Guilherme Rodrigues]

I thought I was cursed when, all of the sudden, concurrent stopped working altogether while working on CLEAN, my fork of MEAN.

Finally, I returned to the last PC in which it ran OK and, sure enough, it has node v0.10.5 installed.

I have heard it works as far as v0.10.15. Will try it now and report.

Gruntfile is really simple:

grunt.initConfig
  watch:
    public:
      files: ['public/**']
      options:
        livereload: true

  mochaTest:
    main:
      options:
        reporter: 'spec'
      src: ['test/**/*.coffee']

  nodemon:
    main:
      options:
        file: 'server.coffee'
        ignoredFiles: ['node_modules/**', '.idea/**', 'public/**', '.git/**']
        debug: true
        delayTime: 1

  concurrent:
    main:
      tasks: ['watch', 'nodemon']
      options:
        logConcurrentOutput: true

Ah, yes, I tried changing the tasks' order (watch and nodemon) to no avail.

[Guilherme Rodrigues]

Doesn't seem to work on v0.10.15.

Trying 0.10.10 next.

[Guilherme Rodrigues]

Ok, it's not working either. Beginning to think it's not about node version. Why doesn't concurrent loves my Ubuntu 12.04.3 VM? :(

[Guilherme Rodrigues]

My, oh, my...

Turns out, upon inspecting the task's code I stumble upon this snippet here:

var options = this.options({
    limit: require('os').cpus().length
});

Aaaand "That's a bingo!".

My VM only has one virtual CPU. Increasing limit option to 2 solves the problem.

Hope this helps someone, someday. Gonna throw some keywords so folks find this easier:

grunt-concurrent virtualbox virtualization cpu limit one task only

[D]

Was just attempting to deploy a generator-angular project which utilises concurrent on a box that only has 1 core and was getting an error: Error: spawn EACCES. Looked at the documentation and it says grunt-concurrent requires a minimum of 2 cores and it's pointless to use it otherwise.

Yeah it's pointless, but I don't want it to fail, I would much rather it take twice as long on a box with only one core :P I'm guessing this is a technical limitation rather than by choice?

[Sindre Sorhus]

@intellix it doesn't fail when there's only one core, you just don't get any benefit of using this plugin. Your error is probably with something else.