WebStorm / grunt debug run throwing EADDRINUSE error - node.js

Question

I have a Node/Angular app, developed using the WebStorm IDE. I can run the application fine via WebStorm (Shift + F10). However, any time I try to run in debug mode, I am receiving the EADDRINUSE error:
Running "concurrent:default" (concurrent) task
Verifying property concurrent.default exists in config...OK
Files: [no src] -> default
Options: limit=10, logConcurrentOutput
Error: listen EADDRINUSE :::52387
Here is my gruntfile.js - like I said, WebStorm builds and runs it just fine, until I try to run it in debug mode, where it throws the error:
'use strict';
var fs = require('fs');
module.exports = function(grunt) {
// Unified Watch Object
var watchFiles = {
serverViews: ['app/views/**/*.*'],
serverJS: ['gruntfile.js', 'server.js', 'config/**/*.js', 'app/**/*.js', '!app/tests/'],
clientViews: ['public/modules/**/views/**/*.html'],
sass: ['public/css/*.scss'],
clientJS: ['public/js/*.js', 'public/modules/**/*.js'],
clientCSS: ['public/modules/**/*.css'],
mochaTests: ['app/tests/**/*.js']
};
// Project Configuration
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
watch: {
serverViews: {
files: watchFiles.serverViews,
options: {
livereload: true
}
},
serverJS: {
files: watchFiles.serverJS,
tasks: ['jshint'],
options: {
livereload: true
}
},
clientViews: {
files: watchFiles.clientViews,
options: {
livereload: true
}
},
clientJS: {
files: watchFiles.clientJS,
tasks: ['jshint'],
options: {
livereload: true
}
},
clientCSS: {
files: watchFiles.clientCSS,
tasks: ['csslint'],
options: {
livereload: true
}
},
sass: {
files: watchFiles.sass,
tasks: ['sass:dev'],
options: {
livereload: true
}
},
mochaTests: {
files: watchFiles.mochaTests,
tasks: ['test:server'],
}
},
jshint: {
all: {
src: watchFiles.clientJS.concat(watchFiles.serverJS),
options: {
jshintrc: true
}
}
},
csslint: {
options: {
csslintrc: '.csslintrc'
},
all: {
src: watchFiles.clientCSS
}
},
uglify: {
production: {
options: {
mangle: false
},
files: {
'public/dist/application.min.js': 'public/dist/application.js'
}
}
},
cssmin: {
combine: {
files: {
'public/dist/application.min.css': '<%= applicationCSSFiles %>'
}
}
},
nodemon: {
dev: {
script: 'server.js',
options: {
nodeArgs: ['--debug'],
ext: 'js,html',
watch: watchFiles.serverViews.concat(watchFiles.serverJS)
}
}
},
'node-inspector': {
custom: {
options: {
'web-port': 1337,
'web-host': 'localhost',
'debug-port': 5858,
'save-live-edit': true,
'no-preload': true,
'stack-trace-limit': 50,
'hidden': []
}
}
},
concurrent: {
default: ['nodemon', 'watch'],
debug: ['nodemon', 'watch', 'node-inspector'],
options: {
logConcurrentOutput: true,
limit: 10
}
},
env: {
test: {
NODE_ENV: 'test'
},
secure: {
NODE_ENV: 'secure'
},
development: {
NODE_ENV: 'development'
}
},
mochaTest: {
src: watchFiles.mochaTests,
options: {
reporter: 'spec',
require: 'server.js'
}
},
karma: {
unit: {
configFile: 'karma.conf.js'
}
},
sass: {
dev: {
files: {
'public/css/style.css': 'public/css/*.scss'
}
}
},
copy: {
localConfig: {
src: 'config/env/local.example.js',
dest: 'config/env/local.js',
filter: function() {
return !fs.existsSync('config/env/local.js');
}
}
}
});
// Load NPM tasks
require('load-grunt-tasks')(grunt);
// Making grunt default to force in order not to break the project.
grunt.option('force', true);
// A Task for loading the configuration object
grunt.task.registerTask('loadConfig', 'Task that loads the config into a grunt option.', function() {
var init = require('./config/init')();
var config = require('./config/config');
grunt.config.set('applicationJavaScriptFiles', config.assets.js);
grunt.config.set('applicationCSSFiles', config.assets.css);
});
//Sass task
grunt.registerTask('default', ['lint', 'sass:dev', 'concurrent:default']);
// Debug task.
grunt.registerTask('debug', ['lint', 'copy:localConfig', 'concurrent:debug']);
// Secure task(s).
grunt.registerTask('secure', ['env:secure', 'lint', 'copy:localConfig', 'concurrent:default']);
// Lint task(s).
grunt.registerTask('lint', ['jshint', 'csslint']);
// Build task(s).
grunt.registerTask('build', ['lint', 'loadConfig', 'ngAnnotate', 'uglify', 'cssmin']);
// Test task.
grunt.registerTask('test', ['copy:localConfig', 'test:server', 'test:client']);
grunt.registerTask('test:server', ['env:test', 'mochaTest']);
grunt.registerTask('test:client', ['env:test', 'karma:unit']);
};

Answer 1

The problem is caused by the way Grunt spawns child tasks. By default, grunt.util.spawn() inherits main process arguments and starts child process with same options as the main process (--debug-brk=52387), so child process is started on the same debug port as the main process, causing EADDRINUSE. See https://github.com/gruntjs/grunt/issues/1420.
As a workaround, try adding process.execArgv = []; to the top of Gruntfile.js - it should help