Starcraft AI blog

BWAPI 4.3.0 (release page) was released on March 1. Already it warns “This version is known to crash a lot.” Looking at the commits since then, which fix a couple of simple pointer bugs, confirmed for me the impression that quality control was not up to full speed for this release.

The change log lists mostly welcome but minor items: Documentation fixes and clarifications (always valuable), 2 fixes that prevent kinds of cheating that I wasn’t aware of, and 4 bug fixes to correct crashes or wrong behavior. There is one more substantial feature, which is that latency compensation has been “rewritten from scratch with turn size awareness.” Looking at the issue thread, I see that the new code is generalized to work in more cases, and some known misbehaviors are fixed. And it notes that latency compensation is hard and it’s still nothing like perfect, which is hardly surprising.

If you’re running 4.2.0, obviously you don’t want to upgrade to a version that crashes often. But if you want to try it out, theoretically you should be able to just drop in the new BWAPI library. You might want to test whether any of the fixes affect your bot. To me it seems entirely possible that rewriting something tricky like latency compensation could introduce new bugs, and anyone who reports those will help everybody.

Steamhammer is still running 4.1.2, and I plan to move it to 4.2.0 soon. That’s more effort, because I have to switch compilers. It seems that the version that fixes 4.3.0’s new bugs will be 4.4.0 (rather than 4.3.1 as I would expect), and it should also be a drop-in replacement for 4.2.0. For now, my expectation is that I’ll run 4.2.0 for a while, and wait to see if 4.4.0 proves stable and is supported by tournaments.