There isn't a way to tell if there has been an error I'm afraid. A return value could be good though...
Have you tried using the absolute latest from http://www.espruino.com/binaries/git/commit_date/?
I recently updated to a more recent filesystem library and rewrote bits of the SPI interface, so you might find that it fixes your problems.
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
There isn't a way to tell if there has been an error I'm afraid. A return value could be good though...
Have you tried using the absolute latest from http://www.espruino.com/binaries/git/commit_date/?
I recently updated to a more recent filesystem library and rewrote bits of the SPI interface, so you might find that it fixes your problems.