I'm not sure what the upshot of this is.
Currently, the tests test images and other bundles by starting up a subsidiary lisp, and then checking its console output.
Writing a dribble file wrapper around that will be pretty painful.
For now I propose to continue to use build.exe and buildi.exe for Windows, pending a re-think of how the lisp-invocation library (which we use for testing) should handle console output on windows.
As Faré points out, our tests are single-threaded, so this seems adequate for now.
If I'm missing something, please LMK.
Otherwise, I will probably press on to release 3.1.6.
P.S. I don't have time to do a whole lot of debugging of the SBCL + run-program issue right now, although I have been able to replicate it.