Just got back from holiday and tried upgrading trusty to xenial again...
My first attempt hit this bug again. However then I found that unplugging my USB DVB tuner solved it. So now I'm finally able to keep xenial installed.
Next step was to plug the USB DVB tuner back in and test the above xenial fix. Un/fortunately this bug has suddenly stopped happening for now, so I don't have a reliable system to test the xenial fix on, at least for today.
Just got back from holiday and tried upgrading trusty to xenial again...
My first attempt hit this bug again. However then I found that unplugging my USB DVB tuner solved it. So now I'm finally able to keep xenial installed.
Next step was to plug the USB DVB tuner back in and test the above xenial fix. Un/fortunately this bug has suddenly stopped happening for now, so I don't have a reliable system to test the xenial fix on, at least for today.