> You have to choose (mode or --mode) between two modes now: production or development.

I think what we have here is the start of a new era for heisenbugs to thrive.

The reason I suspect so is because a lot of JavaScript packages are written in awkward ways that makes lots of assumptions about the packages loaded, the order of the load, monkey patching require, and a whole lot of other oddities.

With current setup, you can disable various plugins and optimizations to pin point the conditions under which a bug manifests.

With new release, now you have to figure out what is the current state of the configurations to begin-with and how changing modes impacts that.