Comment 5 for bug 1560188

I've tracked it down to this indicator-datetime landing:

https://requests.ci-train.ubuntu.com/#/ticket/893

Downgrading indicator-datetime to the version below (or simply stopping it before following the repro steps above) prevents the freeze.

https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/stable-phone-overlay/+sourcepub/5495431/+listing-archive-extra