Why fastboot devices is empty on Linux?
I misunderstood what does it mean to boot to fastboot mode. By reading through tutorials I thought when I saw the screen on the screenshot, I still needed to boot (power button) into fastboot mode. Turns out that when I saw that screen above, I was already in fastboot mode and could issue the unlock or flash commands.

Looking at some more detailed Youtube videos made that clear. After tackling a typo I successfully flashed TWRP, installed SuperSU. The OP3 DayDream mod is not working yet though: DayDream apps still displayed as not compatible with my phone in the app store, even after the XML modification and reboot.

One extra advice: a simple adb backup -all won't backup everything, as I learned.

https://forum.xda-developers.com/oneplus-3t/help/oneplus-3t-fastboot-ubuntu-16-10-t3561732?goto=newpost



During 2017 summer I managed to get the DayDream hack working, I used SuperSU. I just transitioned to Magisk, so I can use Android Pay and hardware tokens. The DayDream hack does not work since the last couple of OS updates in the fall.