I apologize, but I think I am going to have to proclaim ECL on Windows as officially unsupported by ASDF.
There are underlying bugs in ECL on Windows that preclude ASDF functioning correctly. To the best of my knowledge, there isn't anyone able to maintain ECL on Windows, and given that, attempting to keep ASDF working on that platform just piles up failing tests. With apologies, as of now I am removing "ecl_bytecodes" from my Windows test suite (I was already unable to test vanilla ECL because of not having a C compiler on Windows). If there are patches available and a means of verifying them, I would like to see Windows ECL support come back, but at the moment the community seems entirely unable to support this platform. Note that ECL is still supported on Mac OS X and Linux.
