Electrum 3.0 zombie after quit

[makishart]

Hi, I upgraded in electrum 3.0 I started a new wallet because the wallet update wasn't successful. Whenever I try to shutdown the window disappears but the app hangs in the background until I kill it from the task manager. I am running it on opensuse tumbleweed.
I also tried deleting the wallet and start a new empty one but the result was the same.

[AbdussamadA]

duplicate of #3023

[makishart]

I actually didn't have the same issue in previews versions..
Shall I close this issue?

[ecdsa]

not sure if that really is a duplicate of #3023 .. the descriptions seem to differ

[makishart]

Ok.. Let me know if I can help with any specific info or if it is a common issue for opensuse tumbleweed..

[ecdsa]

@makishart it would be useful to kknow if this issue occurs when you run electrum from a terminal

[makishart]

Yes, since that happened the first few times, I only run it from the terminal now. When I quit electrum then the terminal hangs until I Ctrl+c or close the terminal to force close electrum. During the hang the tray icon is active and the menu pop up on right click but nothing happens. Can't quit or retrieve the application.

[ecdsa]

do you quit it using the menu?

[makishart]

Both ways.. Clicking the x button or using quit from the menu has the same effect..

[AbdussamadA]

It is the same issue in the sense that it won't quit and you have this icon in the systray that doesn't do anything. You can't get the window to appear if you click on the systray icon and you can't exit via the right click menu of the icon.

[makishart]

Yes.. but this is a different version.. I had not the issue before 3

[AbdussamadA]

The systray issue also started with version 3.

[fr3aker]

It looks like self.app started in ElectrumGui.main() is never stopped which causes the stall. Calling self.app.quit() in ElectrumWindow.clean_up() seems to fix the problem but I'm not familiar with QT and Electrum's GUI code and don't know if this is the proper fix. (it's probably not because that defeats the purpose of the tray, which does not work for hiding/restoring anyway, see #3023)

[JackDinn]

hmm, just updated to electrum 3.0.2 because i would have thought this would have been fixed but no its still there. Looks like i still have to use killall electrum to shut it down, maybe next update ???

Mint 18.2
KDE plasma 5.8.8

[SomberNight]

I've reproduced this. More specifically,

• using a config based on @AbdussamadA's description (from Can't Restore From System Tray #3023 (comment)): OpenSUSE Leap 42.3 with KDE
• when using Electrum with the QT GUI, after closing all the windows, the process does not quit

I'm unsure if #3023 is the same problem (duplicate or not).

Even more specifically, the main thread of the app runs

electrum/gui/qt/__init__.py

Line 252 in 9d4dd20

self.app.exec_()

and the exec_ call will never return.

To be fair, the QT docs mention that exec might not return on some platforms, but the docs look (to me) to be concerned with OS shutdown and similar cases. They suggest to connect to the QCoreApplication::aboutToQuit signal instead of expecting exec to return.

In this specific case, not even aboutToQuit is emitted.

QGuiApplication::lastWindowClosed is emitted however, and QGuiApplication::quitOnLastWindowClosed() is True, which based on the same docs, should result in the app quitting, but this does not happen for some reason. We can however connect our own slot to lastWindowClosed to fix this.

[JackDinn]

does not seem to have been fixed. Built from master,

Closing the main GUI via window close button kills the tray icon.
File/Quit or Tray/Exit Electrum leaves the /usr/local/bin/electrum running (but does kill the tray icon).

Kernel: 4.10.0-42-generic x86_64 (64 bit) Desktop: KDE Plasma 5.11.4 Distro: neon 16.04 xenial

[SomberNight]

@JackDinn I've now tested with latest LTS (5.8) and latest non-LTS (5.11) KDE neon, and haven't been able to reproduce the issue. The Electrum process properly quits for me.

[JackDinn]

@SomberNight yea , it could be related to my neon Dev OS, Iv had a lot of trouble with it recently and yesterday i decided to drop it. Im using Manjaro KDE now but learning a completely new package management system means i was out of my depth trying to build Electrum from source so i shall just stick with the community package for now (3.0.3-1). Thank you for taking a look though and the excellent work you do too.

[AbdussamadA]

@SomberNight I tested git master on openSUSE and it works fine. Thanks!