STEPS TO REPRODUCE (on Mac): 1) python ../obj-firefox/_tests/testing/mochitest/runtests.py --debugger=gdb 2) At the gdb prompt, type "run" EXPECTED RESULTS: Program starts under gdb ACTUAL RESULTS: (gdb) run Starting program: /Users/bzbarsky/mozilla/vanilla/obj-firefox/dist/MinefieldDebug.app/Contents/MacOS/firefox-bin -foreground -no-remote -profile /Users/bzbarsky/mozilla/vanilla/obj-firefox/_tests/testing/mochitest/mochitesttestingprofile/ http://localhost:8888/tests/ Reading symbols for shared libraries ++++.++++++++++++............................................................................................. done ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to /Users/bzbarsky/mozilla/vanilla/obj-firefox/_tests/testing/mochitest/mochitesttestingprofile/leaks-report.log *** Registering components in: Apprunner Program exited with code 06. (gdb) ADDITIONAL INFORMATION: I put a breakpoint in _exit, and tried running. After the "*** Registering components in: Apprunner" nothing happens. GDB stops responding (no response to Ctrl-C or Ctrl-Z). If I kill gdb from a different terminal, the Firefox process completes shutdown immediately. A breakpoint in |exit| is never hit, so _exit is presumably being called directly.

Hm... WFM, on OS X.

OK, so we must be doing something differently.... I wonder what. It clearly doesn't WFM, on any of my builds.

Updating xcode did not help.

I don't fully understand the underlying cause here, I had a problem with the same symptoms that appears to be caused by gdb and the crash reporter somehow fighting over who gets what signal handlers. I was able to work around it by using 'unset env MOZ_CRASHREPORTER' before 'r' in gdb.

(In reply to comment #4) > I was able to work around it by using 'unset env MOZ_CRASHREPORTER' before 'r' > in gdb. Yeah, that seems to fix it for me too.

Comment on attachment 392952 [details] [diff] [review] Proposed fix env['MOZ_CRASHREPORTER_NO_REPORT'] = '1' - env['MOZ_CRASHREPORTER'] = '1' + if crashreporter: + env['MOZ_CRASHREPORTER'] = '1' Just stick both environment variable settings under the if block. + proc = Process([cmd] + args, + env = environment(env, xrePath = xrePath, + crashreporter = not debuggerInfo), stdout = outputPipe, stderr = subprocess.STDOUT) Can you make the indentation of the argument list consistent while you're here? I don't know if there's a similar example in this file to be consistent with, but make it internally consistent.

Pushed http://hg.mozilla.org/mozilla-central/rev/496552354668 with those changes. Tanks for the review and the help on finding the place to fix!

Hmm. This is failing for me again. Did something break in the last month?

Reopening, per comment 9. :( I'll see if I can figure out what's going on here.

Pushed http://hg.mozilla.org/mozilla-central/rev/6282a369f3ec to fix the new breakage.

(In reply to comment #12) > Pushed http://hg.mozilla.org/mozilla-central/rev/6282a369f3ec to fix the new > breakage. That should be wanted for m-1.9.2 and m-1.9.1 too.

If you want to try to get this in on those, go for it. I don't end up debugging mochitests much on branches, so don't feel a strong need to do that.

We appear to have a regression here: I'm running into this exact problem on recent trees, and it's freezing in the exact spot as (and with the same symptoms as) described in Bug 500126 comment 1.