v1.3.1

Aren't you excited for the imminent release of Go 1.21 with GOOS=wasip1 GOARCH=wasm? We are!

wazero 1.3.1 is a minor release with important changes. No public APIs have been affected in any way, but we improved portability and further moved forward support to nonblocking I/O, especially on Windows!

Remember to star wazero, and check our community for other cool wazero users like you!

Improve Support to Cross-Compilation

@SlashScreen noticed (#1578) that builds for GOOS=plan9 were failing due to some missing constant definitions; this is somewhat related to an earlier issue reported by @supermigo (#1526) that prevents building wazero against the new GOOS=wasip1 GOARCH=wasm target pair with Go 1.21.

@codefromthecrypt has led a spike (#1582, #1584, #1586, #1588) of refactorings to decouple our core from the direct dependency on the syscall package, which is obviously highly platform-specific; for instance, some error codes or flags may only exist on some platforms: referring to such constants in shared code paths prevents a successful cross-platform build. #1582 introduces sys.Errno as an abstraction over platform-specific error codes, and #1586 defines fsapi.Oflag to abstract over file open flags.

If you are interested in that kind of oddity, support to GOOS=wasip1 will allow you to run a wasm wazero on a native wazero because self-hosting is the ultimate test for a runtime, but also because... why not? 🔥

Improve Nonblocking I/O

This release is also improving support for nonblocking I/O, first by fixing a bug (#1538) that was originally addressed with #1542, but ultimately was not completely resolved. @johanbrandhorst reported that the Go CI was still producing corrupted output when writing to a redirected stdout. @evacchi uncovered the root cause of the bug rather quickly; in fact, most time was spent writing an automated test case that reproduced the conditions of the Go CI (i.e. spawning a stand-alone wazero process and hooking that stdout to a buffer). This was fixed with #1581.

Notably, @evacchi moved issue #1500 another step closer to resolving, i.e., nonblocking I/O on Windows, by emulating select using a few different Windows APIs. Details on how this has been realized are described in #1579 and are summarized in /RATIONALE.md. Further work is still needed to close the gap in poll_oneoff.

Minor changes

• @abraithwaite contributed the RunReveal project to community page (#1577)
• @codefromthecrypt bumped the CI version of Go to the latest Go 1.21rc3 (#1589)