[hibby]

If you read the script, it copies the relevant qemu binary on line 52 to the chroot's /usr/bin/.

What's happening here is binfmt-support on the host has a path registered for arm binaries as the file you just copied to /usr/bin - whenever the chroot tries to run anything, the host directs it to this bianry which is your arm emulator :).

[jimmies]

That's an awesome explanation - thanks! I just copied and pasted from other people's code and prettified it a bit so it's easier to use, but I didn't really understand why it worked. Now I do a bit better.