this is the only browser chrome test case that fails while running inside an ubuntu 12.04 virtual machine. I spent a day trying to debug this and didn't get anywhere. We need somebody to look at this. Here is what we see in the log: 12:42:56 INFO - TEST-START | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js 12:42:56 WARNING - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | uncaught exception - uncaught exception: 2147746065 at :0 12:42:56 WARNING - This is a harness error. 12:42:56 INFO - Stack trace: 12:42:56 INFO - JS frame :: chrome://mochikit/content/tests/SimpleTest/SimpleTest.js :: simpletestOnerror :: line 1067 12:42:56 INFO - native frame :: <unknown filename> :: <TOP_LEVEL> :: line 0 12:42:56 INFO - TEST-INFO | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | Console message: [JavaScript Error: "uncaught exception: 2147746065"] 12:43:26 WARNING - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | Test timed out 12:43:26 WARNING - This is a harness error. 12:43:26 INFO - args: ['/builds/slave/test/build/tests/bin/screentopng'] 12:43:26 INFO - Xlib: extension "RANDR" missing on display ":0". 12:43:29 WARNING - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | Cleanup function threw an exception at chrome://browser/content/tabbrowser.xml:1536 - TypeError: aTab is null 12:43:29 WARNING - This is a harness error. 12:43:29 INFO - INFO TEST-END | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | finished in 30058ms 12:43:29 WARNING - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/browser/devtools/debugger/test/browser_dbg_createChrome.js | Found a tab after previous test timed out: http://example.com/browser/browser/devtools/debugger/test/browser_dbg_stack.html 12:43:29 WARNING - This is a harness error. 12:43:29 INFO - TEST-INFO | checking window state https://tbpl.mozilla.org/php/getParsedLog.php?id=19101423&tree=Cedar#error0

FTR, This VM uses Xvfb for X.

this is blocking us from migrating over our browser chrome test. Can somebody from the developer tools team lend a hand to aid in fixing this?

I tried running the test in an Ubuntu 12.10 VirtualBox VM I have here and the test completed successfully. I ran the test using mach: ./mach mochitest-browser browser/devtools/debugger/tests/browser_dbg_createChrome.js If that is not how you ran the test, can you try this so we can see if its specific to the way you set up the environment? Comment 1 mentions using Xvfb, but it's been years since I used that, so perhaps one of you guys could save me some time by posting the steps required to do that?

you can run Xvfb like this: $ Xvfb :0 -screen 0 1600x1200x24 Generate vnc password (need tightvncserver package): $ vncpasswd Then attach x11vnc $ x11vnc -display :0 -rfbauth ~/.vnc/passwd -forever -shared Now you can VNC to that host, something like this: $ vncviewver -via $user@$host localhost

we run the tests the same way they do in automation from buildbot (i.e. there is no source tree or toolchain on the box). I download a tar.bz2 and a tests.zip file from a build directory (i.e. http://ftp.mozilla.org/pub/mozilla.org/firefox/tinderbox-builds/mozilla-central-linux/1360077863/) I unzip them, then I run the command: python mochitest/runtests.py --appname=firefox/firefox-bin --utility-path=bin --extra-profile-file=bin/plugins --certificate-path=certs --autorun --close-when-done --console-level=INFO --symbols-path=http://ftp.mozilla.org/pub/mozilla.org/firefox/tinderbox-builds/mozilla-central-linux/1360077863/firefox-21.0a1.en-US.linux-i686.crashreporter-symbols.zip --browser-chrome I will look at the mach command locally and see how it differs, there might be something I can do to copy all the necessary bits to the machine.

I figured this out. We are trying to setup the debuggerserver port on 6000 and that is the port that xfvb is listening on. I was able to get this test passing by changing the pref devtools.debugger.remote-port to something else (I chose 6023). Are there any concerns with my adding this new pref/setting to our automation script?

I am fine with that, thanks!