build: windows/arm (32-bit ARM) port is broken

[dmitshur]

The Go porting policy has a section on broken ports, https://go.dev/wiki/PortingPolicy#broken-ports. The GOOS=windows GOARCH=arm (not arm64) port was marked broken in August 2024 (CL 601777) for the following reasons:

• The port stopped working, failing to build with make.bat, tracked in issue runtime: problem with preemption on windows arm32 #68552.
• The builder stopped running, and no new running builder has been added yet, tracked in x/build: add LUCI windows-arm builder #67308. (A running builder is needed to know whether the port is working.)

This is an umbrella issue to track the status of the port.

CC @golang/windows, @golang/release.

[gabyhelp]

Related Issues

• x/build: add a Windows ARM64 builder #42604 (closed)
• x/build/env/windows/arm64: windows/arm64 builders are down #57408 (closed)
• x/build: add a Windows ARM32 builder #46492 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[gopherbot]

Change https://go.dev/cl/634077 mentions this issue: _content/doc/go1.24: document broken windows/arm port

[qmuntal]

IMO, the important fact here is that windows/arm32 has been broken since Go 1.17 and nobody complained until now, almost 4 years later. Additionally, Windows 11 no longer supports arm32, not even via arm64 to arm32 emulation. From https://learn.microsoft.com/en-us/windows/arm/arm32-to-arm64:

Windows devices running on an Arm processor (for example, Snapdragon processors from Qualcomm) will no longer support AArch32 (Arm32).

Given these facts, I'm inclined to remove the windows/arm32 port altogether. This will also help making the Windows port easier to maintain, as it's one less architecture to touch when refactoring the compiler and the runtime.

[mcandre]

Please elide broken platforms from go tool dist list.

That mechanism can act as a single source of truth for working platforms, so that dev utilities like factorio can function without requiring constantly republishing manual lists of broken ports.

https://github.com/mcandre/factorio

Could there be a Go stdlib API member, so we don't need to shell out every time?

[dmitshur]

@mcandre go tool dist list already leaves out broken ports by default. Broken ports can be listed too by passing in the -broken flag.

$ go version
go version go1.24.0 darwin/arm64
$ go tool dist list | grep windows/arm
windows/arm64
$ go tool dist list -broken | grep windows/arm
windows/arm
windows/arm64

$ GOTOOLCHAIN=go1.17.13 go tool dist list | grep windows/arm
windows/arm
windows/arm64

That was issue #56679.

There's no package in the standard library that's a good fit for this, and this information can changes only in major Go releases, so at most once every 6 month, so executing a cmd/dist shouldn't be too onerous. If you still think there's more to do, please file a separate issue for that, since this issue is about the window/arm port specifically. Thanks.

[mcandre]

On the other hand, factorio should probably not couple to any Go package to obtain this information, as the version of Go will vary from project to project. So shelling out is probably necessary.

However, the logic that go tool dist list uses should be promoted to some package in the standard library regardless. For general code cleanliness and for yet other uses.