Ubuntu on Lenovo Thinkpad T450s

Lenovo’s T450s is another piece of high-production-volume hardware from a vendor with a fairly good reputation for Linux support … but a host of serious problems under Ubuntu’s flagship “Long-term-support” operating system.  I’d love to be in touch with others running this machine, to know whether these are all common symptoms for you:

Hardware-ish Problems as of June 2016:

• This has varied in its details with updates since I first installed, but currently my laptop cannot shut down at all. When I shut it down with software, it just hangs on the moving-dots screen. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1573597
• Undocking the laptop from Lenovo’s superdock (to which I have a Wacom tablet attached) makes unity-settings-daemon crash, which leads to various secondary failures until I’ve rebooted twice. Not infrequently, the machine locks up. https://bugs.launchpad.net/ubuntu/+source/unity-settings-daemon/+bug/1439427 [Update: fix released to xenial-proposed]
• After booting, RAM use steadily climbs to fill nearly all of the 20GB I have, even though nothing is using it https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1585598
• Fingerprint scanner keeps flashing after use, requiring second/useless scan https://bugs.launchpad.net/ubuntu/+source/fprintd/+bug/1588815
• Disabling of the touchpad while typing, a standard feature to avoid the mouse pointer jumping around randomly, does not work. This old(!) bug report contains a work-around; the -t option of syndaemon is not working, so should not be used: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1581491

Beyond that, there are various software problems with Ubuntu 16.04. I have filed bugs about apt-mark hold, banshee, biber [update: fix released], etc. But these are not particular to my hardware.

Also, for some bizarre reason, although I more or less maxed out the specs on this machine, the keyboard backlight does not work, which apparently means I bought one without! Careful not to do that.