Bug#819096: Frequent hangs/crashes when changing network configuration

[Ben Hutchings]

Package: gnome-shell
Version: 3.18.4-1
Severity: serious

[Marking this serious because we must not release a version of
gnome-shell that does this on most machines.  If it's specific to
mine, I accept that this should be downgraded.]

If I change the network configuration through the right hand menu in
GNOME Shell it may hang for 10 seconds or (apparently) indefinitely.
This seems particularly likely to happen when switching between wifi
and mobile broadband (3G modem).  It's entirely possible there's an
underlying Network Manager bug here, but it's still unacceptable for
that to block the shell (and thus the entire user interface).

Ben.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.4.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages gnome-shell depends on:
ii  dconf-gsettings-backend [gsettings-backend]  0.24.0-2
ii  evolution-data-server                        3.18.5-1
ii  gir1.2-accountsservice-1.0                   0.6.40-3
ii  gir1.2-atspi-2.0                             2.18.3-4
ii  gir1.2-caribou-1.0                           0.4.20-1
ii  gir1.2-clutter-1.0                           1.24.2-1
ii  gir1.2-freedesktop                           1.46.0-4
ii  gir1.2-gcr-3                                 3.18.0-1
ii  gir1.2-gdesktopenums-3.0                     3.18.1-1
ii  gir1.2-gdm-1.0                               3.18.2-1
ii  gir1.2-gkbd-3.0                              3.6.0-1
ii  gir1.2-glib-2.0                              1.46.0-4
ii  gir1.2-gnomebluetooth-1.0                    3.18.2-1
ii  gir1.2-gnomedesktop-3.0                      3.18.2-1
ii  gir1.2-gtk-3.0                               3.18.9-1
ii  gir1.2-gweather-3.0                          3.18.1-1
ii  gir1.2-ibus-1.0                              1.5.11-1
ii  gir1.2-mutter-3.0                            3.18.3-2
ii  gir1.2-networkmanager-1.0                    1.1.91-3
ii  gir1.2-nmgtk-1.0                             1.1.91-1
ii  gir1.2-pango-1.0                             1.38.1-1
ii  gir1.2-polkit-1.0                            0.105-14.1
ii  gir1.2-soup-2.4                              2.52.2-1
ii  gir1.2-telepathyglib-0.12                    0.24.1-1.1
ii  gir1.2-telepathylogger-0.2                   0.8.2-1
ii  gir1.2-upowerglib-1.0                        0.99.4-2
ii  gjs                                          1.44.0-1
ii  gnome-backgrounds                            3.18.0-1
ii  gnome-icon-theme-symbolic                    3.12.0-1
ii  gnome-settings-daemon                        3.18.2-1
ii  gnome-shell-common                           3.18.4-1
ii  gsettings-desktop-schemas                    3.18.1-1
ii  libatk-bridge2.0-0                           2.18.1-3
ii  libatk1.0-0                                  2.18.0-1
ii  libc6                                        2.22-3
ii  libcairo2                                    1.14.6-1
ii  libcanberra-gtk3-0                           0.30-2.1
ii  libcanberra0                                 0.30-2.1
ii  libclutter-1.0-0                             1.24.2-1
ii  libcogl-pango20                              1.22.0-2
ii  libcogl20                                    1.22.0-2
ii  libcroco3                                    0.6.11-1
ii  libdbus-glib-1-2                             0.106-1
ii  libecal-1.2-19                               3.18.5-1
ii  libedataserver-1.2-21                        3.18.5-1
ii  libgcr-base-3-1                              3.18.0-1
ii  libgdk-pixbuf2.0-0                           2.32.3-1.2
ii  libgirepository-1.0-1                        1.46.0-4
ii  libgjs0e [libgjs0-libmozjs-24-0]             1.44.0-1
ii  libglib2.0-0                                 2.46.2-3
ii  libgstreamer1.0-0                            1.6.3-1
ii  libgtk-3-0                                   3.18.9-1
ii  libical1a                                    1.0.1-0.1
ii  libjson-glib-1.0-0                           1.0.4-2
ii  libmozjs-24-0                                24.2.0-3
ii  libmutter0g                                  3.18.3-2
ii  libnm-glib4                                  1.1.91-3
ii  libnm-util2                                  1.1.91-3
ii  libpango-1.0-0                               1.38.1-1
ii  libpangocairo-1.0-0                          1.38.1-1
ii  libpolkit-agent-1-0                          0.105-14.1
ii  libpolkit-gobject-1-0                        0.105-14.1
ii  libpulse-mainloop-glib0                      8.0-1
ii  libpulse0                                    8.0-1
ii  libsecret-1-0                                0.18.4-1
ii  libstartup-notification0                     0.12-4
ii  libsystemd0                                  229-2
ii  libtelepathy-glib0                           0.24.1-1.1
ii  libx11-6                                     2:1.6.3-1
ii  libxfixes3                                   1:5.0.1-2+b2
ii  mutter                                       3.18.3-2
ii  python3                                      3.5.1-2
ii  telepathy-mission-control-5                  1:5.16.3-2

Versions of packages gnome-shell recommends:
ii  gdm3                        3.18.2-1
ii  gkbd-capplet                3.6.0-1
ii  gnome-contacts              3.18.1-1
ii  gnome-control-center        1:3.18.2-1
ii  gnome-themes-standard-data  3.18.0-2
ii  gnome-user-guide            3.18.1-1
ii  iio-sensor-proxy            1.1-1
ii  unzip                       6.0-20

gnome-shell suggests no packages.

-- debconf-show failed