Comment 16 for bug 1806269

I've built a package containing the fix patch (taken from Debian's 1.8.10-3) and tested to confirm it solves the issue when gnome-keyring is NOT installed.

$ apt list --installed network-manager-gnome gnome-keyring
Listing... Done
network-manager-gnome/bionic-updates,now 1.8.10-2ubuntu2 amd64 [installed]

$ nm-connection-editor

(nm-connection-editor:4086): GLib-GIO-CRITICAL **: 15:48:24.298: g_dbus_proxy_new: assertion 'G_IS_DBUS_CONNECTION (connection)' failed
Segmentation fault (core dumped)

$ sudo dpkg -i ../libnm-gtk0_1.8.10-2ubuntu3_amd64.deb ../libn
ma0_1.8.10-2ubuntu3_amd64.deb ../gir1.2-nm*.deb ../network-manager-gnome_1.8.10-2ubuntu3_amd64.deb

...

$ nm-connection-editor

(nm-connection-editor:2009): GLib-GIO-CRITICAL **: 15:43:26.561: g_dbus_proxy_new: assertion 'G_IS_DBUS_CONNECTION (connection)' failed

And the GUI editor opened on the connection.

The built package can be found at:

https://launchpad.net/~tj/+archive/ubuntu/bugfixes