I get that you probably just want to win an argument, for the sake of winning an argument, and most likely you're not actually interested in getting some software to run on your niche operating system.
But, just for the far fleeting chance that you are actually interested in doing the right thing:
1. I did not claim that the "oras" binary was the only incompatibility. I guessed your quick judgement was based on that binary being vendored for one platform only and showed that it does exist for other platforms. The latter clearly does not imply the former.
2. Ocicl developers claiming it "only works on Linux" is not a promise they make to you. You cannot hold them at gotcha-gunpoint just in case the software happens to run on a non-Linux OS. They are not interested in playing a game of gotchas with you.
They _are_ being clear: they have only tested it to work on Linux. It is you that misreads it, probably because, I'm guessing, you aren't familiar with the language of OSS READMEs