all: remove support for windows/arm

[qmuntal]

Proposal Details

The windows/arm port, which runs on a Windows with 32-bit ARM architecture, has been broken and unable to initialize the Go runtime since Go 1.18 (see #68552 and #70705). Even more, we haven't got a builder for ages.

From the Windows side, 32-bit ARM is no longer supported on Windows 11, as per these docs: 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).

As a maintainer of the Go Windows port, having to keep up with the windows/arm port when changing the Go standard library (mainly the runtime package) is tedious and time consuming. Even if it doesn't really work, CI test that at least it can be cross-compiled, so I can't just pretend it doesn't exist.

Having said all these arguments, I propose to remove the windows/arm port support from the Go toolchain, tentatively targeting Go 1.25.

@golang/windows @golang/release

[gabyhelp]

Related Issues

• build: windows/arm (32-bit ARM) port is broken #70705
• all: port to Windows/ARM32 #26148
• runtime: windows arm32 1.22 broken #68996 (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/648795 mentions this issue: all: remove support for windows/arm

[kristibektashi]

First of all, thank you for keeping and maintaining the ARM32 Windows version of go for as long as you have (even if it broken and even if it eventually gets removed).

And second, I personally disagree with this proposal. There IS demand for the windows/arm version of go, not on the ARM64 versions of Windows before version 24H2 (although it should also continue to run there as well for ease of testing and debugging), but on older, ARM32-only versions of Windows running Windows RT (some of which can also run a special version of Windows 10 for the ARM32 architecture) since it is the only version of go what would run on these devices.

Although such devices are rare nowadays, there are people (like me) who do have them, and being able to run software based on go is a blessing for us due to the limited application support that these devices have always had.

I also want to note that demand for ARM32 Windows software is rising as people are digging up their old devices since more and more software is being ported. In fact, there is an entire comunnity based on porting software to such devices (and just bringing back life to them in general), and they're fairly active: Link to OpenRT Discord server.

As for the port itself, both of the issues that the ARM32 Windows port had have been fixed by @wmjb (#70234, #68996), and both the builder as well as the CI tests should run just fine on an ARM64 device running Windows 10 ARM64 or Windows 11 ARM64 up to version 23H2 (since these can run ARM32 apps), on in an emulated QEMU device running ARM32 Windows 10: https://files.open-rt.party/Miscellaneous/qemu-win10-15035-arm32.7z.

With all that said, I personally believe the windows/arm port of go should not be removed, since the OpenRT community can be expected to use it and provide bug reports, testing and pull requests in case something breaks. Some of them may even be willing to set up their own builders for the platform in order for it to continue to be supported and tested.

@qmuntal I want to hear your thoughts on this, and if you're still inclined to remove the windows/arm port, I also have an alternative proposal that I would like you to hear first.