"node" executable throws errors on hosted browsix example

[jbeard4]

The node executable in the browsix example hosted here throws an error Path must be a string. Received undefined.

Steps to reproduce:

1. Visit https://unix.bpowers.net/
2. Run node. Note the following error in the Chrome JavaScript console:

Uncaught TypeError: Path must be a string. Received undefined
    at assertPath (kernel.js:447)
    at Object.resolve (kernel.js:479)
    at Syscalls.open (kernel.js:2050)
    at AsyncSyscalls.open (kernel.js:1699)
    at Kernel.doSyscall (kernel.js:2469)
    at Task.syscallHandler (kernel.js:2871)

Note that this also breaks the shell, which stops responding to user input.

3. Run node -e 'console.log("hello")'. Note the following error appears in the bash console: error: -2