Comment 15 for bug 1388130

Another possible hint: some in this set of packages currently in vivid proposed breaks the WiFi password dialog:

Calculating upgrade... Done
The following NEW packages will be installed:
  libisl13
The following packages will be upgraded:
  apport apport-gtk btrfs-tools fontconfig fontconfig-config
  gir1.2-timezonemap-1.0 gnome-system-monitor libc-bin libc-dev-bin libc6
  libc6-dbg libc6-dev libc6-i386 libcloog-isl4 libdb5.3 libfontconfig1
  libjasper1 libqt5qml5 libqt5quick5 libtbb2 libtimezonemap-data
  libtimezonemap1 multiarch-support python3-apport python3-problem-report
  qml-module-qtquick-localstorage qml-module-qtquick-window2
  qml-module-qtquick2 qtdeclarative5-localstorage-plugin
  qtdeclarative5-qtquick2-plugin syslinux syslinux-common
32 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 21.4 MB of archives.
After this operation, 2,157 kB of additional disk space will be used.

As none of these packages seem directly related, but libc is being updated, I'm wondering if the issue is a ABI mismatch in a codepath only being triggered on Utopic Unity systems (as I also noticed that network-manager seemingly wasn't rebuilt at any time during Utopic).

So my next test is a no-change rebuild of network-manager for Utopic...