5.8 nightlies ship x86 only docc binary

[finestructure]

Description

As described here, the 5.8 nightlies ship a x86 only binary, which makes documentation generation fail on arm64 Macs without Rosetta.

Checklist

• If possible, I've reproduced the issue using the main branch of this package.
• This issue hasn't been addressed in an existing GitHub issue.

Expected Behavior

docc should be a universal binary.

Actual behavior

No response

Steps To Reproduce

No response

Swift-DocC Version Information

No response

Swift Compiler Version Information

No response

[ethan-kusters]

Thanks for filing this @finestructure! This seems to have been a problem since docc began shipping in the Swift.org toolchain (including release and development toolchains):

% file /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64]
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift (for architecture x86_64):	Mach-O 64-bit executable x86_64
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift (for architecture arm64):	Mach-O 64-bit executable arm64

% file /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/docc
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/docc: Mach-O 64-bit executable x86_64

% file /Library/Developer/Toolchains/swift-5.6-DEVELOPMENT-SNAPSHOT-2022-03-31-a.xctoolchain/usr/bin/docc
/Library/Developer/Toolchains/swift-5.6-DEVELOPMENT-SNAPSHOT-2022-03-31-a.xctoolchain/usr/bin/docc: Mach-O 64-bit executable x86_64

% file /Library/Developer/Toolchains/swift-5.7.1-RELEASE.xctoolchain/usr/bin/docc
/Library/Developer/Toolchains/swift-5.7.1-RELEASE.xctoolchain/usr/bin/docc: Mach-O 64-bit executable x86_64

[ethan-kusters]

This issue also seems to affect swift-format:

% file /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift-format
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2022-11-19-a.xctoolchain/usr/bin/swift-format: Mach-O 64-bit executable x86_64

[finestructure]

Thanks for taking a look and confirming it's an issue, @ethan-kusters !

Just in terms of our planning to ship the docc-preview feature, do you have a sense of how complicated a fix this is?

I'm asking because the only workaround for us is to install Rosetta on our builders, which we can't then uninstall. (The reason we're a little reluctant to do that is that it's a new dependency which we'd like to avoid for our builder setup if possible.)

This is not a huge deal but if you feel like a fix is a few days or a week or two away then we could hold off finalising that feature until there's a fixed nightly toolchain available.

[ethan-kusters]

Let me do a little more investigation today – it seems like the fix may be fairly simple.

[ethan-kusters]

rdar://102870094

[ethan-kusters]

@finestructure this should be available in the next nightly toolchain! You can also download the one attached to this CI build if you'd like to test it out sooner: https://ci.swift.org/job/swift-PR-toolchain-macos/418/

[finestructure]

Fantastic, thanks @ethan-kusters ! I've run my test with that PR's toolchain and it works as expected 👌

[ethan-kusters]

Unfortunately, this broke nightly toolchain builds. Reverted with swiftlang/swift#62369.

It looks like SwiftPM supports building for multiple architectures with the configuration we need, but not testing. @neonichu is looking into a fix. The PR job for building toolchains doesn't run tests so we didn't catch this before merging.

@finestructure it should be possible to work around this issue by reverting the revert in swiftlang/swift#62369 in a draft PR whenever you need a new toolchain and requesting a macOS toolchain from CI. Since the PR CI doesn't run tests that should continue to work until we get this resolved in the nightly builds.