I think the only thing pip could do is to stop using print(), which is not a reasonable request.

It may be reasonable to change pythonw to use dummy IO streams by default, but that may cause programs to print() messages expecting the user to see them. It's also likely a breaking change for many programs, so I do think handling the ensurepip case like this is best.

Just realised that I probably ought to make the same fix for __stderr__, in case pip succeeds but tries to write a warning there that causes the installer to detect a failure. Assume an equivalent line of code to set stderr/__stderr__ if needed.