In `setBreakpoint` in dbg-client.jsm, we resume the thread if we had to interrupt it to set the breakpoint. The `resume` called at the end of the function should only happen if the pause type is "interrupt". There's probably a race condition in there so we should add the check for good measure.
Created attachment 8479270 [details] [diff] [review] bp-interrupt.patch Unfortunately, I wasn't able to write a failing test. I was able to write a test that printed out an error message when we hit the race, but I couldn't create an assertion that failed with the error message. Either way, this change made the error message go away. Try push: https://tbpl.mozilla.org/?tree=Try&rev=993df2622b70
Created attachment 8479273 [details] [diff] [review] non-failing-test-case.patch For posterity, this is the test case that I could get an error message to be printed without the previous patch applied, but couldn't get it to actually fail any assertions.