Fails silently if only reporter is missing

[foxyblocks]

Expected behavior

If the plugin is missing for the only configured reporter (e.g. karma-mocha-reporter), karma should exit with an error status.

Actual behavior

It does not run any tests and gives no failure. Only a log warning:

17 05 2016 13:28:27.831:WARN [reporter]: Can not load "mocha", it is not registered!
  Perhaps you are missing some plugin?
17 05 2016 13:28:27.851:WARN [karma]: No captured browser, open http://localhost:9876/
17 05 2016 13:28:27.857:INFO [karma]: Karma v0.13.22 server started at http://localhost:9876/

Enviroment Details

• Karma version: 0.13.22

module.exports = function(config) {
  config.set({
    frameworks: ['jasmine'],
    reporters: ['mocha'],
    files: ['tests/**/*']
    //...
  });
};

Steps to reproduce the behaviour

1. Create simple project set reporter to ['mocha'], but do not install the plugin for that reporter
2. karma start

[hpurmann]

I can reproduce this. It fails with

30 06 2016 17:34:11.356:ERROR [reporter]: Can not load reporter "mocha", it is not registered!
  Perhaps you are missing some plugin?
30 06 2016 17:34:12.782:INFO [karma]: Karma v1.1.0 server started at http://localhost:9876/
30 06 2016 17:34:12.782:INFO [launcher]: Launching browser Firefox with unlimited concurrency
30 06 2016 17:34:12.783:ERROR [karma]: Found 1 load error

but the exit code is 0.

[benwill]

Running into same issue

[johnjbarton]

Based on reading the current code this bug should have been fixed. Please reopen if you see it again.