x/mobile/cmd/gomobile: issues linking frameworks in Xcode

[taybart]

What version of Go are you using (go version)?

go: 1.11.1 (also 1.11 and 1.10.3 were tested)
gomobile: master (a27dd33d354d004b2de14a791df5af8a00f68b8e)
Xcode: 10.1 (10B61)

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/taybartski/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/taybarski/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/Cellar/go/1.11.1/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.11.1/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/vw/bxwt77n10r90nc1dbrjgt31m0000gn/T/go-build422606684=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

[This was after gomobile/golang/xcode update]

I was successfully using gomobile bind, it seems that something with the build process has changed. I have a .framework that I generated last week that still works, however, the new ones that I create are failing to link in the newest Xcode.

The output below was generated with the example from the wiki. This may be an Xcode issue, but the fact that the old .framework is still compiling makes be think it may be in gomobile.

Looking at the lastest change that happened in gomobile, it seems unlikely that it is that. I am at a loss though. Xcode was updated along with the command line tools. Any insight would be very helpful.

What did you expect to see?

Successful linking of .framework

What did you see instead?

Xcode error:

ld: warning: ignoring file /Users/taybartski/go/src/golang.org/x/mobile/example/bind/ios/Hello.framework/Hello, file is universal (4 slices) but does not contain the x86_64 architecture: /Users/taybartski/go/src/golang.org/x/mobile/example/bind/ios/Hello.framework/Hello
Undefined symbols for architecture x86_64:
  "_HelloGreetings", referenced from:
      -[ViewController loadView] in ViewController.o
ld: symbol(s) not found for architecture x86_64

$ file Hello.framework/Hello
Hello.framework/Hello: Mach-O universal binary with 4 architectures: [arm_v7:current ar archive] [arm64]
Hello.framework/Hello (for architecture armv7): current ar archive
Hello.framework/Hello (for architecture i386):  current ar archive
Hello.framework/Hello (for architecture x86_64):        current ar archive
Hello.framework/Hello (for architecture arm64): current ar archive

[taybart]

ld command:

Ld /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Products/Debug-iphonesimulator/Hello.app/Hello normal x86_64 (in target: Hello)
    cd /Users/taybartski/dev/projects/Hello
    export IPHONEOS_DEPLOYMENT_TARGET=12.0
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk -L/Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Products/Debug-iphonesimulator -F/Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Products/Debug-iphonesimulator -F/Users/taybartski/dev/projects/Hello -F/Users/taybartski/dev/projects/Hello/Hello -filelist /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Intermediates.noindex/Hello.build/Debug-iphonesimulator/Hello.build/Objects-normal/x86_64/Hello.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -mios-simulator-version-min=12.0 -dead_strip -Xlinker -object_path_lto -Xlinker /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Intermediates.noindex/Hello.build/Debug-iphonesimulator/Hello.build/Objects-normal/x86_64/Hello_lto.o -Xlinker -export_dynamic -Xlinker -no_deduplicate -Xlinker -objc_abi_version -Xlinker 2 -fobjc-link-runtime -L/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -add_ast_path -Xlinker /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Intermediates.noindex/Hello.build/Debug-iphonesimulator/Hello.build/Objects-normal/x86_64/Hello.swiftmodule -Xlinker -sectcreate -Xlinker __TEXT -Xlinker __entitlements -Xlinker /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Intermediates.noindex/Hello.build/Debug-iphonesimulator/Hello.build/Hello.app-Simulated.xcent -framework Libjourney -Xlinker -dependency_info -Xlinker /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Intermediates.noindex/Hello.build/Debug-iphonesimulator/Hello.build/Objects-normal/x86_64/Hello_dependency_info.dat -o /Users/taybartski/Library/Developer/Xcode/DerivedData/Hello-czuinjavcxpbnxgmovcdbcxuijgw/Build/Products/Debug-iphonesimulator/Hello.app/Hello

Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin18.0.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[taybart]

Reinstalling macOS fixed the issue for me. I don't like that as a fix though...

[zhj4478]

@taybart @gopherbot @sashabaranov
I have the same issue previously.
I found I have binutils(v2.3.2) installed through the homebrew that overrides the same libs from the macOS. After I unlink the binutils the issue is solved. I also tried to downgrade it to (v2.3.1) and it works as well.

I hope this could help who has a similar issue like this.

[karvar]

I am running into the same issue with adding my framework to Xcode. I think that reinstalling macOS is not a fix I would think is feasible. binutils did not work for me either. I am adding the .framework to a cocoapod and the podspecs are as follows:

  s.source_files = [
    'SDK/Classes/*.swift',
    'SDK/Classes/SHTTP.framework/**/*',
  ]
  s.exclude_files = 'SDK/Classes/SHTTP.framework/Versions/**/*'
  s.pod_target_xcconfig = {
    'OTHER_LDFLAGS' => '$(inherited) -ObjC'
  }

My binary file is as follows:

$ file HTTP.framework/HTTP 
HTTP.framework/HTTP: Mach-O universal binary with 4 architectures: [arm_v7:current ar archive random library] [arm64]
HTTP.framework/Pokemon (for architecture armv7): current ar archive random library
HTTP.framework/Pokemon (for architecture i386):  current ar archive random library
HTTP.framework/Pokemon (for architecture x86_64):        current ar archive random library
HTTP.framework/Pokemon (for architecture arm64): current ar archive random library

[karvar]

I added it as a vendored framework and still having the same issue:
s.ios.vendored_frameworks = ['Sdk.framework', 'HTTP.framework']