1495308 - Debugging with VS2017 broken with launcher process enabled

Status: RESOLVED FIXED

(Firefox :: General, defect)

Description

[Jan Henning [:JanH]]

Attachment: My mozconfig

Since the launcher process landed, attempting to launch a debugging session from Visual Studio seems to end in an infinite loop where Firefox keeps launching a new child process and then terminates itself. Backing out https://hg.mozilla.org/mozilla-central/rev/cffbe101e63b returns things to normal again.

Visual Studio is up-to-date and the Child Process Debugging Tool is installed and enabled.

Comment 1

[(No longer employed by Mozilla) Aaron Klotz]

Jan, I am assuming that you're using the Visual Studio Solution that is generated by our build system?

Does it work better after applying the patch from bug 1495481 and then re-running |mach configure|?

Comment 2

[Jan Henning [:JanH]]

(In reply to (PTO Oct 2 - Oct 9) Aaron Klotz [:aklotz] from comment #1)
> Jan, I am assuming that you're using the Visual Studio Solution that is
> generated by our build system?

Yes, I did.

> Does it work better after applying the patch from bug 1495481 and then
> re-running |mach configure|?

Yes, with that patch applied starting a debugging session works normally.

The other issue I've noticed now that launching Firefox through the VS solution actually works, is that the diagnostic tools are now stuck showing memory and CPU usage of the launcher process. It's not a terrible issue, because having that around was more like some nice-to-have background info which with e10s enabled was somewhat incomplete anyway because it only covered the parent process, but with the launcher process it has become really useless now.

Short of making this a runtime option (like "mach run --disable-e10s" as per https://groups.google.com/d/msg/mozilla.dev.platform/xSyK4r54Ifs/D26BlaomAgAJ) I don't think there's a solution for *that*, though.

Comment 3

[(No longer employed by Mozilla) Aaron Klotz]

Thanks, I'm going to mark this bug as fixed.

We'll have some more discussion about the other stuff in dev-platform.