Missing error handler on `socket`. TypeError: (msg || "").replace is not a function Error

I’m getting the above error when I try to run jenkins jobs using karma. Any ideas what could be causing this?

Expected behavior

karma runs angular2 tests on jenkins, they run fine on desktop.

Actual behavior

`Missing error handler on `socket`.
TypeError: (msg || "").replace is not a function
    at /home/hudson/.hudson/jobs/workspace/example/node_modules/karma/lib/reporter.js:45:23
    at onBrowserError (/home/hudson/.hudson/jobs/workspace/example/node_modules/karma/lib/reporters/base.js:58:60)
    at null.<anonymous> (/home/hudson/.hudson/jobs/workspace/example/node_modules/karma/lib/events.js:13:22)
    at emitTwo (events.js:100:13)
    at emit (events.js:185:7)
    at onKarmaError (/home/hudson/.hudson/jobs/workspace/example/node_modules/karma/lib/browser.js:95:13)
    at Socket.<anonymous> (/home/hudson/.hudson/jobs/workspace/example/node_modules/karma/lib/events.js:13:22)
    at emitOne (events.js:95:20)
    at Socket.emit (events.js:182:7)
    at Socket.onevent (/home/hudson/.hudson/jobs/workspace/example/node_modules/socket.io/lib/socket.js:335:8)
    at Socket.onpacket (/home/hudson/.hudson/jobs/workspace/example/node_modules/socket.io/lib/socket.js:295:12)
    at Client.ondecoded (/home/hudson/.hudson/jobs/workspace/example/node_modules/socket.io/lib/client.js:193:14)
    at Decoder.Emitter.emit (/home/hudson/.hudson/jobs/workspace/example/node_modules/component-emitter/index.js:134:20)
    at Decoder.add (/home/hudson/.hudson/jobs/workspace/example/node_modules/socket.io-parser/index.js:247:12)
    at Client.ondata (/home/hudson/.hudson/jobs/workspace/example/node_modules/socket.io/lib/client.js:175:18)
    at emitOne (events.js:90:13)`

Enviroment Details

• Karma version (output of karma --version):
• Relevant part of your karma.config.js file
• node --version v5.7.0
• npm --version 3.6.0 karma version 0.13.21

Steps to reproduce the behaviour

1. run tests in jenkins, (independent of the tests running) the above stacktrace is displayed

[randyaa]

i fixed this locally by adding the following lines to karma/lib/reporter.js @ line 45:

      if ( typeof msg !== "string") {
          msg = JSON.stringify(msg);
      }

so at least there’s output

[tlefevre]

@dignifiedquire there’s still a problem to be fixed and that is the error message. It is very unhelpful and it would be very much appreciated by the community, I’m guessing, if the quality of that was improved. As shown here, the problem was a missing file. A missing file error would be much more appropriate and helpful to users.

Update: My problem was IntelliJ messing up imports in a spec. It couldn’t handle angular2 dependencies properly and gave the wrong path. Build worked fine, but testing failed.