> Handle what?

Handle this situation.  But I guess it's not needed because noone should
normally have '/homeless-shelter'.

I was testing a package from its build directory and forgot to unset
some variables ($HOME, for instance).

> What was the error message exactly?

guix build: error: build failed: directory `/homeless-shelter' exists;
please remove it

> unless running as root.

Well, my understanding is that it shouldn't be harmful (under normal
circumstances) for the main system.  But it's not smart because you
could affect the chroot itself, which is not desirable anyway.  So, I'm
going to use '--userspec' from now on.

Thanks for the heads up.