proposal: doc: document that Go 1.14 is last to support darwin/arm (32bit version)?

[dmitshur]

iOS 13 (and iPadOS 13) does not support running 32-bit apps. iOS 10 was the last version that supported 32-bit apps (with very visible warnings), and it's 3 years old.

Is it time to remove darwin/arm (leaving just darwin/arm64)? If so, the first step would be to document that Go 1.14 will be the final release with darwin/arm support.

Related to #34749. /cc @bradfitz @hyangah @eliasnaur

[eliasnaur]

Other than the builder, darwin/arm support isn't too much extra hassle than just darwin/arm64.

Go runs on watchOS and tvOS now, and the first darwin/arm64 watch (Watch Series 4) was released just a year ago. Earlier models are 32-bit.

@steeve might care; he had reservations last time I asked. Steeve also runs the hardware darwin/arm builder which has been offline for quite a while.

[bradfitz]

Not having a builder is another good reason to delete it.

That's actually our official policy: https://github.com/golang/go/wiki/PortingPolicy#removing-a-port

[dmitshur]

Thanks for providing that information Elias. I was thinking about watchOS and tvOS but wasn't sure what the state of their 32->64-bit migration was.

From looking over https://en.wikipedia.org/wiki/Apple_TV, I understand the current Apple TV devices (4th and 5th generations) support 64-bit (only?), but 3rd generation (released in 2013, discontinued in 2016) did not.

It sounds like watchOS devices aren't as far along, but iOS/iPadOS and tvOS are.

[steeve]

We are planning on removing arm support in a few weeks/months (most likely when we migrate to xcode 11). Although not just yet.

Supporting older WatchOS hardware looks like a pretty good reason to keep it though since it can now run Go (and I mean, how cool is that), which is fairly new with 1.13.

The builder being off-line is on me though, I'll fix that tomorrow morning.

[eliasnaur]

@dmitshur, I briefly considered AppleTV. Only the 4th generation support the App Store, so we don't need 32-bit support for AppleTV.

[steeve]

I have restarted the darwin_arm and darwin_arm64 builders. 🤞

[eliasnaur]

I have restarted the darwin_arm and darwin_arm64 builders. crossed_fingers

If only it was that easy: https://farmer.golang.org/temporarylogs?name=darwin-arm64-mn4m2zdaios&rev=cedb561617ea40c72dc018b38c4d5f0862595fe8&st=0xc0020f51e0

ERROR: Could not connect to lockdownd, error code -21

[steeve]

ERROR: Could not connect to lockdownd, error code -21

Alas, libimobiledevice needed an update, and somehow one of the iPhones wouldn't pair with the computer unless itunes was launched. Should be good now.

EDIT: it wasn't good, missing env vars. Should be better now.

[eliasnaur]

Still no luck:

error: The specified item could not be found in the keychain.
go_darwin_arm_exec: codesign: exit status 1
FAIL	bytes	0.277s