@hoodmane,@freakboy3742 rather than a platform-specific check for this one test, could you make it so theset_blocking /get_blocking general platform feature flag which the test is also guarded by fails instead? Are a number of other tests intest_os that use that sort of check. Worried this platform specific check would end up needing to be copied to general libraries to support Emscripten. Python'sio library has strong non-blocking support in its lower layers, and a number of projects / libraries rely on specific guarantees + file bugs and fixes.

@cmaloney That's definitely an approach that wecould take - it's an approach that iOS and Android use for a bunch of APIs in the "they exist, but you can't call them" category. However, in this case, it's not 100% clear if the issue here is a bug in Emscripten itself. If it is, then a test skip seems more appropriate. If it turns out there is a fundamental limitation that prevents Emscripten from avoiding the problem causing this test failure, then I'd agree guarding the entire feature would make sense.