Launching preferences crashes Spyder when using PySide

[aleksandaratanasov]

Hi!

I have the latest version of Spyder (master branch) and I'm starting it via the bootstrap.py script. My setup is Ubuntu 14.04 (64bit) with 3.13.0 kernel, up-to-date software.

Reproduce:

• start Spyder (in my case via bootstrap.py)
• click on the Preference item in the main menu

What is expected to happen:
Opens Spyder's preferences window

What happens:
Spyder crashes with segmentation fault (core dumped) error

I saw there was an issue in 2014 (#1903) where the IDE crashed when using the preferences though the issue has been closed and it's also not very clear what the issue was or how to reproduce it so this might either be this same issue or a new one.

[ccordoba12]

Please try to run

spyder --reset

and try again. That should solve the problem.

[aleksandaratanasov]

Thanks for the fast reply. I can't run spyder just like this because it cannot find the spyderlib. That is why I'm using the bootstrap.py in the first place. ;)

I would have installed it but my user is not part of the sudo group so I have to deal with the bootstrapping thing. Any ideas how to go around it?

[ccordoba12]

Sorry, I didn't notice that you mentioned you're using bootstrap :-)

In that case you need to run

python bootstrap.py -- --reset

to reset your preferences.

[aleksandaratanasov]

Sorry for the late reply but I didn't have access to the machine where I have this problem on. I tried your suggestion, it reset the settings yet Spyder still crashes. Btw I have this error message all the time while the IDE is running:

X Error: BadCursor (invalid Cursor parameter) 6
  Major opcode: 2 (X_ChangeWindowAttributes)
  Resource id: 0x3

When I load something the opcode changes to 95. Don't know if this has anything to do with the crash though but I thought it might be useful information.

[ccordoba12]

This is a problem with PySide, as I discovered some time ago. So please use Spyder with PyQt4 or PyQt5.

We won't support PySide officially since Spyder 3.0, although we will try to fix major issues like this one.

[Nodd]

I encountered crashes with pyside when the underlying C++ object was destroyed, but not the python object. I don't remember the details though...

[Nodd]

After some googling (googleing ?) I found that python's gc and qt's gc are sometimes interacting with each other. It's fixed by keeping a reference to some temporary objects, but it'll be hard to find the correct one.
See for example:
http://stackoverflow.com/questions/19211430/pyside-segfault-when-using-qitemselectionmodel-with-qlistview
http://stackoverflow.com/questions/27928807/pyside-segfault-on-shutdown

[goanpeca]

@Nodd It was working before, so we can bisect and see what has changed since then...

[aleksandaratanasov]

Frankly I am surprised that Spyder actually runs PySide. I didn't even know it was installed on the system I'm working on. Is there a way to tell bootstrap to use PyQt instead? I haven't written a single application with PySide and since Spyder crashes when it uses it I see no reason why no prevent it from looking for it to begin with.

[ccordoba12]

We supported PySide until Spyder 2.3, but we decided to drop official support for it since 3.0. This means that the core team is not going to solve more bugs related to PySide, and instead we expect the community helps us to maintain it.

To use bootstrap with another binding, you need to pass to it the gui option, like this

python bootstrap --gui=pyqt5

(pyqt5 will be our default option for Spyder 3) or

python bootstrap --gui=pyqt

[aleksandaratanasov]

Thanks, will do that.

[CAM-Gerlach]

@ccordoba12 Can we close this, now that we haven't supported PySide for a long time, and it seems unlikely anyone really uses it anymore at least with Spyder 3.x+? This is the last remaining issued tagged PySide, and with it we could close out the tag. Also, at some point would it be a good idea to go through our 600+ open issues and remove any that are no longer valid or relevant? Thanks!

[ccordoba12]

Yep, we can.

[ccordoba12]

Also, at some point would it be a good idea to go through our 600+ open issues and remove any that are no longer valid or relevant?

Oh yeah, that would help us a lot!

[CAM-Gerlach]

Cool, thanks. I'll go through them after my key tasks for 3.2.7 are complete.