Opening "Preferences" results in segfault on macOS (crash, QtMultimedia camera handling)

[bitkarrot]

See attached file for crash report. Happens when clicking on 'preferences' or while closing open wallets.
electrum_crash.txt

[SomberNight]

Happens when clicking on 'preferences'

Maybe that's related to QtMultimedia and the camera-handling...

Could you test going into the Console tab (menubar>View>Show Console), and then running:

from PyQt5.QtMultimedia import QCameraInfo

Also, to try to narrow things down, could you test if Electrum 4.1.5 also reproduces the crash?

crash happens [...] while closing open wallets

if you mean during application shutdown (e.g. closing last open wallet), that might be #6889

[bitkarrot]

Could you test going into the Console tab (menubar>View>Show Console), and then running:

from PyQt5.QtMultimedia import QCameraInfo

this import actually returns nothing.

tried to repeat the 'preferences' crash from last night. i noticed that just open/closing wallets today its okay. when new wallets are closed and opened, that's when the crash happens, sometimes on preferences, sometimes when closing wallets.

i'm on bigsur 11.6 if that helps.

when i get a chance to uninstall i'll try out the earlier version

if you mean during application shutdown (e.g. closing last open wallet), that might be #6889

yes, its definitely #6889

[bitkarrot]

i installed the .dmg, not sure if that had an impact.

perhaps i should run from source? (need to set up dev environment anyway ;)

will try to install from source, and then see if i can get anything from the cli

[danshao]

Also crashes on non M1.

I'm on Mac OS Monterey 12.3 Macbook Air 2019. Crash occurs whenever I hit the Preferences menu button.

[SomberNight]

Could either of you specifically test the following steps:

• start Electrum, open a wallet
• go into the Console tab (menubar>View>Show Console), and then run:

  from PyQt5.QtMultimedia import QCameraInfo
  

• open Preferences, see if it crashes

That is, assuming the crash is related to QtMultimedia, I would like to test whether it helps to run the import before the Preferences dialog is opened.

[danshao]

Does not crash after I type that into console.

[bitkarrot]

Mine does not crash anymore when the above is run.

Could either of you specifically test the following steps:

* start Electrum, open a wallet

* go into the `Console` tab (menubar>`View`>`Show Console`), and then run:
  ```
  from PyQt5.QtMultimedia import QCameraInfo
  ```

* open Preferences, see if it crashes

That is, assuming the crash is related to QtMultimedia, I would like to test whether it helps to run the import before the Preferences dialog is opened.

[SomberNight]

Thanks. So this seems identical to the issue described in Electron-Cash#1545.
I could not so far reproduce this (tried on macos 10.15.3 and 11.3).

Regardless, looking at that PR, it seems #7727 might be enough to fix this.
Would either of you be able to test running from source, try to reproduce, and see if #7727 works?

[bitkarrot]

i checked out SomberNight:202203_qtcamera_preferences_crash

on M1 Apple, Big Sur, version 11.6

built fine, however pycryptodomex', 'cryptography missing from the build process and also #6948

$  ./run_electrum
Error: Failed to load libsecp256k1.
E | ecc_fast | libsecp256k1 library failed to load. exceptions: [OSError('dlopen(/Users/bitcarrot/electrum/electrum/libsecp256k1.0.dylib, 6): image not found'), OSError('dlopen(libsecp256k1.0.dylib, 6): image not found')]

I can try to build this on an intel mac later tonight see if we can get an electrum working.

[bitkarrot]

I was able to get libsecp256 issue resolved, by installing bitcoin-core version,( https://github.com/bitcoin-core/secp256k1#build-steps, make sure built with --enable-module-recovery) however Building on Apple M1 Big Sur has issue with PyQt5, as posted in Dec 2021, see issue also described here:
bordaigorl/rmview#119

I will try rosetta to get PyQt5 installed tomorrow when i have time and see if that can get electrum running on this OS

[bitkarrot]

Problem solved for running from source:
An alternative to getting PyQt5 installed on Apple M1 Big Sur:
https://www.zhihu.com/question/437075754/answer/1993415429

Do the following since pip install pyqt5 won't work:

brew install pyqt5
echo 'export PATH="/opt/homebrew/opt/qt@5/bin:$PATH"' >> ~/.zshrc
echo 'export PATH="/opt/homebrew/opt/pyqt@5/5.15.4_1/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

Running it and clicking 'Preferences' is ok. Does not crash.
Here are the logs from ./run_electrum on https://github.com/SomberNight/electrum/tree/202203_qtcamera_preferences_crash,

there are some exceptions thrown:

E | asyncio | Task exception was never retrieved
future: <Task finished name='Task-136' coro=<Interface.get_estimatefee() done, defined at /Users/bitcarrot/github/electrum/electrum/interface.py:1093> exception=RequestTimedOut("request timed out: ('blockchain.estimatefee', [2]) (id: 6)")>
Traceback (most recent call last):
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 171, in send_request
    response = await asyncio.wait_for(
  File "/opt/homebrew/Cellar/[email protected]/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/tasks.py", line 442, in wait_for
    return await fut
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/session.py", line 540, in send_request
    return await self._send_concurrent(message, future, 1)
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/session.py", line 512, in _send_concurrent
    return await future
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/curio.py", line 382, in __aexit__
    raise TaskTimeout(self._secs) from None
aiorpcx.curio.TaskTimeout: task timed out after 30s

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 1100, in get_estimatefee
    res = await self.session.send_request('blockchain.estimatefee', [num_blocks])
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 175, in send_request
    raise RequestTimedOut(f'request timed out: {args} (id: {msg_id})') from e
electrum.interface.RequestTimedOut: Network request timed out.
E | asyncio | Task exception was never retrieved
future: <Task finished name='Task-135' coro=<Interface.get_estimatefee() done, defined at /Users/bitcarrot/github/electrum/electrum/interface.py:1093> exception=RequestTimedOut("request timed out: ('blockchain.estimatefee', [5]) (id: 5)")>
Traceback (most recent call last):
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 171, in send_request
    response = await asyncio.wait_for(
  File "/opt/homebrew/Cellar/[email protected]/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/tasks.py", line 442, in wait_for
    return await fut
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/session.py", line 540, in send_request
    return await self._send_concurrent(message, future, 1)
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/session.py", line 512, in _send_concurrent
    return await future
  File "/Users/bitcarrot/Library/Python/3.9/lib/python/site-packages/aiorpcx/curio.py", line 382, in __aexit__
    raise TaskTimeout(self._secs) from None
aiorpcx.curio.TaskTimeout: task timed out after 30s

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 1100, in get_estimatefee
    res = await self.session.send_request('blockchain.estimatefee', [num_blocks])
  File "/Users/bitcarrot/github/electrum/electrum/interface.py", line 175, in send_request
    raise RequestTimedOut(f'request timed out: {args} (id: {msg_id})') from e
electrum.interface.RequestTimedOut: Network request timed out.

[SomberNight]

Running it and clicking 'Preferences' is ok. Does not crash.
Here are the logs from ./run_electrum on https://github.com/SomberNight/electrum/tree/202203_qtcamera_preferences_crash,

Thanks for testing.

there are some exceptions thrown:

 E | asyncio | Task exception was never retrieved
 [...]
 aiorpcx.curio.TaskTimeout: task timed out after 30s

That's unrelated and should be harmless.

[SomberNight]

Ok, so #7727 hopefully fixes this. Closing.

[bitkarrot]

Regarding the build from source notes on Apple M1, is there a place on electrum-docs or elsewhere I can consolidate my notes? It was a bit cumbersome the build process?

Thanks @SomberNight

[SomberNight]

@bitkarrot you can create a file, e.g. notes_for_arm.md inside contrib/osx, and make a PR.