Qt flowgraphs crash on ubuntu 18.04

[Paul Bongaerts]

Did a fresh Ubuntu studio 18.04 bionic install from http://cdimage.ubuntu.com/ubuntustudio/dvd/current/HEADER.html

lsb_release -rd
Description: Ubuntu Bionic Beaver (development branch)
Release: 18.04

apt-cache policy gnuradio
gnuradio:
  Installed: 3.7.11-6
  Candidate: 3.7.11-6
  Version table:
 *** 3.7.11-6 500
        500 http://nl.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

Installed gqrx-sdr which has gnuradio as dependency.

sudo apt-get install update
sudo apt-get install upgrade
sudo apt-get install gqrx-sdr
sudo reboot

Now running flowgraphs with wx-gui or no-gui works fine.
Only when running QT-gui flowgraphs i get the following error:

<<< Welcome to GNU Radio Companion 3.7.11 >>>

Block paths:
 /usr/share/gnuradio/grc/blocks

Loading: "/home/paul/Desktop/untitled.grc"
>>> Done

Generating: '/home/paul/Desktop/top_block.py'

Executing: /usr/bin/python -u /home/paul/Desktop/top_block.py

Warning: failed to XInitThreads()
linux; GNU C++ version 7.2.0; Boost_106501; UHD_003.010.002.000-0-unknown

** (python:7547): WARNING **: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-Yl2hgwWel0: Connection refused

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:597:14: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:597:14: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:600:17: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:784:14: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:784:14: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:787:17: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:1096:14: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:1096:14: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:1099:17: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:2286:8: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:2286:18: Using Pango syntax for the font: style property is deprecated; please use CSS syntax

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:2291:8: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:2291:18: Using Pango syntax for the font: style property is deprecated; please use CSS syntax

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4357:14: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4357:14: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4419:12: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4419:12: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4428:16: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4428:16: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4443:22: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4443:22: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4499:12: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4501:16: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4501:16: Expected a string.

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4549:12: not a number

(python:7547): Gtk-WARNING **: Theme parsing error: gtk.css:4549:12: Expected a string.
QApplication: invalid style override passed, ignoring it.
Traceback (most recent call last):
  File "/home/paul/Desktop/top_block.py", line 123, in <module>
    main()
  File "/home/paul/Desktop/top_block.py", line 111, in main
    tb = top_block_cls()
  File "/home/paul/Desktop/top_block.py", line 57, in __init__
    self.restoreGeometry(self.settings.value("geometry").toByteArray())
AttributeError: 'NoneType' object has no attribute 'toByteArray'

>>> Done

[Vasil Velichkov (vvvelichkov)]

Hi,

Yesterday I reported this bug to Debian, and today I've proposed a patch

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=886807

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "qt5-qtgui-bug886807.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]