shell-init: error retrieving current directory:
getcwd: cannot access parent directories: No such file or
directory
Laughing at myself: switching between tabs in
multi-gnome-terminal, I ran `apt-get update && apt-get
upgrade` from within a directory I had removed, and got that error
message. The clue to the solution and what caused the problem was
'cannot access parent directories: No such file or directory'. A
simple `cd ..` did the trick.