What is the meaning of “Failed building wheel for X” in pip install?

Question

This is a truly popular question here at SO, but none of the many answers I have looked at, clearly explain what this error really mean, and why it occurs.

One sour

Answer 1

Since, nobody seem to mention this apart myself. My own solution to the above problem is most often to make sure to disable the cached copy by using: pip install --no-cache-dir.