Technical disputes over minor, marginal issues conducted while more serious ones are being overlooked. The implied image is of people arguing over what color to paint the bicycle shed while the house is not finished. (jargon file)

Another name for Parkinson's Law of Triviality. It's when an individual or group fixates on discussing trivial issues or ones way outside their area of expertise because the pressing issues they actually need to resolve are too hard for them to constructively engage with.

You know you're the victim of bike shedding when a colleague wants to call a meeting to discuss his face-palmingly idiotic suggestions for your project while deliberately ignoring critical problems of their own that they don't know how to fix or get started with.