That would be "io_uring: support for libuv". Which is a common way to write headlines, so assuming the headline was missing punctuation was reasonable.

(in case the title changes later, it's currently "io_uring support for libuv")

I’m a native speaker, read it wrong at first, and had to think step by step. “well, libuv is a JS-related library, io_ring is an OS level concept, so its probably a change to libuv”, and still had uncertainty and opened GitHub to double check.

You make a really good point I never heard before: X for Y is an ambiguous construct with two names referring to the same class of object, without an obvious relationship. Ex. Barack for Don is easy, but only if you know American politics, a reference to “a predecessor”. But “Jon for Mary” is inscrutable.

Hm? The word “for” has the same meaning here as in “food for kids”. Read it as (io_uring support) for (libuv). “Io_uring support” is being provided. Provided for what? Provided for libuv.

I think this is a slightly different case than the WSL one. The headline is accurate, but perhaps a bit jarring. It might have been better to say "io_uring support in libuv" but I would say using from is not incorrect.

Looking at it again I think the problem is that both X and Y are of the same type which makes the overall sentence confusing, even though it is technically correct.

In a more normal construction ("food voucher support for kids") it is obvious from context that the kids are being given the support, because the converse would be nonsensical.