Safe Mode: Provide fail safe start for Mixxx after it has crashed

[Daniel Schürmann]

Its a bad thing when someone whants to try mixxx and it crashes after start, without any message.

Mixxx should detect that and start in a failsafe mode which is more likly able to start.
This could be achieved to by writing a temp file on mixxx start and delete it on Mixxx shutdown.
If Mixxx finds this file when starting, the last run crashed and it should ask the user if he wants to try the failsafe mode.

Example:
See: Bug #1008999 Segfault on WinXP in Virtual Box using GL Waveforms Edit.
In this case fail save mode is starting with an empty waveform.

[RJ Skerry-Ryan (rryan)]

I would also like to add crash reporting to such a fail-safe system using something like google-breakpad.

[RJ Skerry-Ryan (rryan)]

Related to Bug #1191904 (maybe that one is a dupe of this actually -- oops).

[RJ Skerry-Ryan (rryan)]

I added a --safeMofe command-line flag. It currently:

* Uses empty waveforms.
* Turns off synchronization polling if it was enabled.
* Doesn't auto-open MIDI devices.
* Disables WSpinny.

What else should we do?
https://github.com/mixxxdj/mixxx/commit/c9ebfad121f066c7b38a76417137735102571894

This bug should now just be a matter of:
1) Detecting crashes
2) Enabling safe-mode automatically early on in bootup if we detect we crashed before.

We should be careful because this could be annoying if someone only has a crash on exit -- auto-enabling safe mode will make Mixxx less functional for them. Maybe we can write a check-point when we are about to shut down so that we can tell if we crashed during shutdown versus normal operation.

[RJ Skerry-Ryan (rryan)]

I would call this is a 1.12.0 blocker... we lose too many users to repeated crashes on bootup, etc.

[Owen Williams (ywwg)]

I was thinking, after we detect a crash on shutdown, to pop up a box the next time saying "hey, yo, mixxx crashed, do you want to send us a log?" Of course we'd have to do this before we overwrite the log! We could expand that box to include "do you want to start in safe mode" which would clear out audio config, switch to safe waveforms, and use a conservative skin.

[Daniel Schürmann (daschuer)]

+1 for the pop up.

[Daniel Schürmann (daschuer)]

Related Bug #1380171

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6544