go: cmd/link: c-archive iOS App Store submissions fail without -w

I’ve been using the new golang patches on master for a few days and have been able to run my golang code in the simulator and on tvOS/iOS devices. (Note that I am still using go directly to generate lib.a as outlined above instead of leveraging gomobile).

Now I’m trying to submit an app to the store and running into some weird issues. When submitting to the App Store, I get an email saying processing was stopped:

App Store Connect: Processing stopped for MyApp While processing your iOS app errors occurred in the app thinning process, and your app couldn’t be thinned. If your app contains bitcode, bitcode processing may have failed. Because of these errors, this build of your app will not be able to be submitted for review or placed on the App Store. For information that may help resolve this issue, see Tech Note 2432.

I tried the debugging steps linked in the Tech Note to “rebuild from bitcode” in Xcode, and am getting a strange error about dSYMs missing in IDEDistributionPipeline.log:

ipatool failed with an exception: #<CmdSpec::NonZeroExcitException: Command exited with pid 71395 exit 1:
/Applications/Xcode.app/Contents/Developer/usr/bin/symbols -failIfMissingDsym -symbolsPackageDir /var/folders/_2/hljyy_zj3912lv9qqpy70t5w0000gn/T/ipatool20190324-69852-vd6ut4/thinned-out/arm64/Payload/MyApp.app /var/folders/_2/hljyy_zj3912lv9qqpy70t5w0000gn/T/ipatool20190324-69852-vd6ut4/thinned-out/arm64/Payload/MyApp.app/MyApp
Stdout:
    ERROR: Did not find dSYM for MyApp
    /var/folders/_2/hljyy_zj3912lv9qqpy70t5w0000gn/T/ipatool20190324-69852-vd6ut4/thinned-out/arm64/Payload/MyApp.app/MyApp [arm64, 0.001634 seconds]:

Stderr:
    error: Could not load symbol information for 22D519D5-0C78-3905-8681-93FE91325191.  Symbols file will contain no data.

>
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:248:in `run'
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:2473:in `block in CompileOrStripBitcodeInBundle'
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:2396:in `each'
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:2396:in `CompileOrStripBitcodeInBundle'
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:2628:in `ProcessIPA'
    /Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:3445:in `<main>'

I noticed this:

https://github.com/golang/mobile/blob/6621de06e1e9d52c38a8c542770bdbeac9ecfef6/cmd/gomobile/build_iosapp.go#L74-L75

So I tried again with -ldflags=-w, and that worked! I assumed that wasn’t necessary anymore after bcdbd58ce48d71cb912238caaa193d832901e227 but I guess it is still required.

I am now able to submit builds up to App Store:

App Store Connect: Version 2019 (3.25.619) for MyApp has completed processing.

_Originally posted by @tmm1 in https://github.com/golang/go/issues/22395#issuecomment-476068066_