karma: Karma broken since 1.1.1

Expected behaviour

Tests to pass

Actual behaviour

It is failing with an unspecified error.

+ ./node_modules/.bin/grunt karma:main
14:02:53 Running "karma:main" (karma) task
14:02:53 25 03 2017 14:02:53.103:DEBUG [config]: No config file specified.
14:02:53 25 03 2017 14:02:53.117:DEBUG [plugin]: Loading karma-* from /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules
14:02:53 25 03 2017 14:02:53.118:DEBUG [plugin]: Loading plugin /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-chrome-launcher.
14:02:53 25 03 2017 14:02:53.128:DEBUG [plugin]: Loading plugin /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-firefox-launcher.
14:02:53 25 03 2017 14:02:53.131:DEBUG [plugin]: Loading plugin /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-mocha-reporter.
14:02:53 25 03 2017 14:02:53.143:DEBUG [plugin]: Loading plugin /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-qunit.
14:02:53 25 03 2017 14:02:53.163:DEBUG [web-server]: Instantiating middleware
14:02:53 25 03 2017 14:02:53.165:DEBUG [reporter]: Trying to load reporter: mocha
14:02:53 25 03 2017 14:02:53.168:DEBUG [reporter]: Trying to load color-version of reporter: mocha (mocha_color)
14:02:53 25 03 2017 14:02:53.168:DEBUG [reporter]: Couldn't load color-version.
14:02:53 
14:02:53 START:
14:02:53 25 03 2017 14:02:53.206:INFO [karma]: Karma v1.1.1 server started at http://localhost:9876/
14:02:53 25 03 2017 14:02:53.207:INFO [launcher]: Launching browser Chrome with unlimited concurrency
14:02:53 25 03 2017 14:02:53.216:INFO [launcher]: Starting browser Chrome
14:02:53 25 03 2017 14:02:53.217:DEBUG [temp-dir]: Creating temp dir at /home/jenkins/tmpfs/jenkins-0/karma-7130070
14:02:53 25 03 2017 14:02:53.218:DEBUG [launcher]: /usr/bin/chromium --user-data-dir=/home/jenkins/tmpfs/jenkins-0/karma-7130070 --no-default-browser-check --no-first-run --disable-default-apps --disable-popup-blocking --disable-translate --disable-background-timer-throttling --disable-device-discovery-notifications http://localhost:9876/?id=7130070
14:02:56 25 03 2017 14:02:55.871:DEBUG [web-server]: serving: /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma/static/client.html
14:02:56 25 03 2017 14:02:55.911:DEBUG [web-server]: serving: /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma/static/karma.js
14:02:56 25 03 2017 14:02:56.092:DEBUG [karma]: A browser has connected on socket /#ob4_Mo-nUBR-vN9SAAAA
14:02:56 25 03 2017 14:02:56.104:DEBUG [web-server]: upgrade /socket.io/?EIO=3&transport=websocket&sid=ob4_Mo-nUBR-vN9SAAAA
14:02:56 25 03 2017 14:02:56.105:DEBUG [proxy]: NOT upgrading proxyWebSocketRequest /socket.io/?EIO=3&transport=websocket&sid=ob4_Mo-nUBR-vN9SAAAA
14:02:56 25 03 2017 14:02:56.176:INFO [Chrome 57.0.2987 (Linux 0.0.0)]: Connected on socket /#ob4_Mo-nUBR-vN9SAAAA with id 7130070
14:02:56 25 03 2017 14:02:56.178:DEBUG [launcher]: Chrome (id 7130070) captured in 2.971 secs
14:02:56 25 03 2017 14:02:56.194:DEBUG [web-server]: serving: /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma/static/favicon.ico
14:02:56 25 03 2017 14:02:56.206:DEBUG [middleware:karma]: custom files null null
14:02:56 25 03 2017 14:02:56.207:DEBUG [middleware:karma]: Serving static request /context.html
14:02:56 25 03 2017 14:02:56.210:DEBUG [web-server]: serving: /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma/static/context.html
14:02:56 25 03 2017 14:02:56.219:DEBUG [middleware:source-files]: Requesting /base/node_modules/qunitjs/qunit/qunit.js?c029da7dee0c9cb3b45850a887846f9397b7b0da /
14:02:56 25 03 2017 14:02:56.219:DEBUG [middleware:source-files]: Fetching /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/qunitjs/qunit/qunit.js
14:02:56 25 03 2017 14:02:56.220:DEBUG [middleware:source-files]: Requesting /base/node_modules/karma-qunit/lib/adapter.js?2cc5e3594a3b8ae53e8218929324788866ad223b /
14:02:56 25 03 2017 14:02:56.220:DEBUG [middleware:source-files]: Fetching /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-qunit/lib/adapter.js
14:02:56 25 03 2017 14:02:56.222:DEBUG [web-server]: serving (cached): /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/qunitjs/qunit/qunit.js
14:02:56 25 03 2017 14:02:56.223:DEBUG [web-server]: serving (cached): /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma-qunit/lib/adapter.js
14:02:56 25 03 2017 14:02:56.224:DEBUG [web-server]: serving: /home/jenkins/workspace/mediawiki-core-qunit-jessie/src/node_modules/karma/static/context.js
14:02:57 
14:02:57 Finished in 0.003 secs / 0 secs @ 14:02:56 GMT+0000 (UTC)
14:02:57 
14:02:57 SUMMARY:
14:02:57 ✔ 0 tests completed
14:02:57 25 03 2017 14:02:56.802:DEBUG [karma]: Run complete, exiting.
14:02:57 25 03 2017 14:02:56.802:DEBUG [launcher]: Disconnecting all browsers
14:02:57 25 03 2017 14:02:56.902:DEBUG [launcher]: Process Chrome exited with code 0
14:02:57 25 03 2017 14:02:56.902:DEBUG [temp-dir]: Cleaning temp dir /home/jenkins/tmpfs/jenkins-0/karma-7130070
14:02:57 25 03 2017 14:02:56.937:DEBUG [launcher]: Finished all browsers
14:02:57 Warning: Task "karma:main" failed. Use --force to con

See https://integration.wikimedia.org/ci/job/mediawiki-core-qunit-jessie/14342/console please.

Environment Details

• Karma version (output of karma --version): 1.1.1 with https://gerrit.wikimedia.org/r/#/c/343719/

• Relevant part of your karma.config.js file https://phabricator.wikimedia.org/source/mediawiki/browse/master/Gruntfile.js;162a7a306c20db2693e842070393676159f653e9$80

Steps to reproduce the behaviour

I am unsure how to provide steps that you can run as this fails on a wikimedia jenkin install.

1.1.0 release works for us.