Prints errors to STDERR never STDOUT

This is part of the Semicolon&Sons Code Diary - consisting of lessons learned on the job. You're in the unix category.

Last Updated: 2022-05-26

Webpack version 4.0 printed its stack-traces to stdout. This meant that tools relying on webpack, such as the Ruby wrapper webpacker, could not have an error handling strategy that would simply print out the underlying webpack errors by forwarding the stderr.

Instead they would have to parse the mixed stream dumped into stdout, and since this would be unstable they simply settled on not being able to log errors well (at time of writing - maybe things improved since).