Thanks to @trainailleur, in the mean time, I managed to install UT on the device. FTR, I just had to unlock bootloader via $ fastboot oem unlock before flashing firmware. Radio firmware revision does now match the one from the link in the initial post:

$ adb shell
phablet@ubuntu-phablet:~$ /usr/share/ofono/scripts/list-modems | grep -i rev
    Revision = .4.0.1.c7-00013-M8974AAAAANAZM-1

@trainailleur Thanks, will do so!

As (for the time being) this is a spare device, is there anything I can tests with UT on OPO with the current (legacy) firmware, that UT QA folks are interested in (like camera)?

I have aquired a used OnePlus One (A0001/64GB). Current system seems to be LineageOS 13.1.2 (build date 2016-08-11, build MHC19Q). Baseband version is DI.3.0.c6.00241-M8974AAAAANAZM-1. I do find on the net some hints that there is some 4.x baseband version, e.g., at https://www.reddit.com/r/LineageOS/comments/8c627g/oneplus_one_baseband_report/ Additionally, LineageOS 16 is available for the device.

My question is, how to proceed to finally have UT on the phone with the latest baseband version? I'm a bit lost among the options:

• First install latest Oxygen OS 2.1.4 then UT?
• First install latest Lineage OS 16 (daily) then UT?
• Install new baseband/firmware manually then UT?
• Install UT as is?

Can anybody shed some light on this? Any pointers?

@UniSuperBox No, Mailpile is an email client. From the mailpile faq
What is Mailpile?
Mailpile is software, an e-mail client. It runs on your desktop or laptop computer and you interact with it by using your web browser.
So the frontend is the browser, but the backend is nevertheless meant to be installed on your local device.

I had noticed an N5 getting warm after installing OTA-9, but after rebooting the device works fine. Update was done via adb.

The linked demo looks cool. Just one request to whoever is going to prepare similar videos: Please, do not open a CLI in a UX demo! (Or more generally, when targetting non-developer audience.).

And so simple the fix! Thanks for spotting this!

A few questions that I'd be glad to see clarified (if that's possible today). Not to make a demand, but to know What's in it?:

1. weight: The wiki has 200-235 gram, whereas the initial post has between 168g and 177g. Can you confirm either value (and unit)?
2. sensors: Does the device have an ambient light sensor?
3. GNSS: Is GPS: Yes, with A-GPS, GLONASS a data point or an exhaustive enumeration of GNSS support? (Thinking about Beidou, Galileo. But also: What about SBAS support [WAAS, EGNOS]? Easiest answer would perhaps be some GNSS chip information.)
4. IP class: Any information regarding ingress protection marking?

@mihael Sorry, no idea for wifi problems.

@mihael According to the Arch Linux wiki, when a Device connects, then disconnects after a few moments it might be due a device already being paired (from within a different operating system). A fix is to remove the device and re-pair. The Arch Linux wiki shows how to do that on the command-line via the bluetoothctl command.