Hey, this is also an issue for me if anyone else can report what they did to fix it. I tried running rockboxdev.sh for another platform (m68k-elf) and it shows the location with no issue but for some reason it does not work here. I've tried using the outdated linked VM, windows linux subsystems, and now my own newly created Ubuntu VM. All 3 had the same issue so I have a feeling rockboxdev.sh has some sort of bug (or the guide is missing an important step)