Possible problem on linux with lockfile on some (and not all) computers.

[oskay]

Possible workaround: In Ubuntu I just created a symlink to a fake port with the following incantation

sudo ln -s /dev/ttyACM0 /dev/ttySA0

And though processing complains a little, it doesn't die outright, and the program does run. Apparently this is a processing specific issue?