It's some recent contributed changes that were supposed to improve the 'sandbox' code, but it looks like they broke everything else.
Really sorry about that - I'm trying to fix it ASAP.
@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.
It's some recent contributed changes that were supposed to improve the 'sandbox' code, but it looks like they broke everything else.
Really sorry about that - I'm trying to fix it ASAP.