syscall.Umask not defined when compiling to wasi with tinygo

[mJehanno]

Hello,

I'm using [go-git/go-git] in my side-project. This project is supposed to be a plugin running in [extism] and therefore need to be cmpiled to wasi.

The problem is that when targeting wasi with tinygo I end up with the following error :

../../../go/pkg/mod/github.com/go-git/go-billy/v5@v5.6.2/osfs/os_wasip1.go:30:17: undefined: syscall.Umask
../../../go/pkg/mod/github.com/go-git/go-billy/v5@v5.6.2/osfs/os_wasip1.go:32:11: undefined: syscall.Umask

The way I understand it is that syscall.Umask does not exist in tinygo. I've been told (but could'nt find any matching sources) that tinygo expose an os.Umask instead.

I don't know if this would be the solution to fix compiling to wasi ?

[pjbgf]

@mJehanno that code is only used during tests, so we have more options here.

Do you know if TinyGo has any built-in tags it uses during compilation? If so a new os_wasip1.go could be created that targeted only wasip1 + TinyGo, making that no-op like we do for Windows for example.

[mJehanno]

I checked their doc, especially the ref pages with commands, subcommands and flags (https://tinygo.org/docs/reference/usage/) and found nothing that match go build tags :/

The closest behaviour might be ldflags.

Edit : Confused by this though https://github.com/tinygo-org/tinygo/blob/v0.25.0/targets/wasi.json

[pjbgf]

From that json, it looks like tinygo.wasm might be it. The new os_tinygo_wasip1.go would need //go:build wasip1 && tinygo.wasm and the existing would need the opposite //go:build wasip1 && !tinygo.wasm.

[mJehanno]

Ok, i can try this in local if you want to be sure that it fixes the problem.

[mJehanno]

It seems like it worked even though wasip1 does not seems to be required in os_tinygo_wasip1 (neither in the name nor in the build tags`

The os.Umask does not exist though, I switched to empty func like the one for plan9.

DO you want me to create the PR ?

[pjbgf]

@mJehanno if you could that would be great. The umask is only being used for tests, so if that is a no-op in tinygo we probably can do the same we do for Windows.