Are errors thrown by the fs library catchable?

I've got the following code running, deliberately without having an SD card in the slot, but the catch statement never seems to execute. Am I being stupid?

I see ERROR: Unable to mount media : NOT_READY on the console but not caught an error. If I remove all my console.log, I still get ERROR: Unable to mount media : NOT_READY so I'm assuming it is being logged higher up the stack?

SPI1.setup({ mosi: A7, miso: A6, sck: A5 });
E.connectSDCard(SPI1, B1);

var fs = require("fs");

try {
  fs.readdirSync();
} catch (err) {
  console.log('caught an error');
  console.log(err);
}