Getting platform tools working like I'm used to?

[bastafari]

Mm, I haven't tried fastboot mounting so far.

I didn't have a reason to try it as all of my Android devices are actively used. But I guess I could use my sacrificial Nexus 7 2012 for a quick test during the weekend. Could be the permission (I recall I had to alter the permissions or use sudo ages ago on some Ubuntu install).

Out of curiosity, what is the target Android device?

Currently I'm using a OnePlus 7 Pro.  It's strange in that it's the first device I've had with an a/b partition. So if I'm rom hopping I sometimes have to boot twrp recovery from fastboot then install it. But right now I foreseeably wouldn't be able to even oem unlock a new device.  I'm thinking this is an arm issue as anbox had had issues bring compiled, as I've seen in other threads. No problems on other linux machines.