Downloading code to Espruino without WebIDE

Ahh, interesting - I thought it was the opposite (that cu was non-exclusive, and tty was exclusive?). Surprising that it doesn't recognise the tty ports though - the tool itself doesn't do any filtering so I assume the issue is with serialport (although it's written by someone who I believe is mainly a Mac user, so I assume he has good reasons for only allowing cu access).

I'm actually working on Linux, where there don't seem to be cu devices - so I have to use tty :)