Even that varies based on your ability to find an alternative. If, say, you're a well-spoken geeky-looking white guy with a degree from a decent school, the worst-case scenario from a complete meltdown is something like “I took a job one cube over from Dilbert at <big corp> which has trouble keeping developers”.

The further you deviate from that (not fluent in the right language, from the wrong minority/gender, self-taught, etc.) the more reasonable it is to question how a failure will impact your ability to get jobs at your level or even stay in the field.