zig cc -target aarch64-macos-gnu fails with FrameworkNotFound when used with cgo

[charleskorn]

Zig Version

0.9.0

Steps to Reproduce

I've created a repository https://github.com/charleskorn/zig-cgo-libs that contains a sample project, build script (./build.sh) and GitHub Actions workflow (sample build) that demonstrates the problem.

To reproduce this for yourself, clone the repository and run ./build.sh.

The tl;dr appears to be: when using Zig as a C compiler for Golang's cgo, Zig fails to find the CoreFoundation framework if -target is specified explicitly. ie. zig cc -target aarch64-macos-gnu ... fails, but if I compile on my M1 Mac with no -target, the build succeeds.

I've passed --sysroot with the path provided by xcrun --show-sdk-path, as suggested in #10299 (comment).

Expected Behavior

Build succeeds.

Actual Behavior

Build fails with a FrameworkNotFound error, and a warning that the framework could not be found (and that there are no framework search paths):

warning(link): framework not found for '-framework CoreFoundation'
warning(link): Framework search paths:
error: FrameworkNotFound

I can see zig is being invoked with the expected arguments, for example:

zig cc -target aarch64-macos-gnu --sysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -I /opt/homebrew/Cellar/go/1.17.5/libexec/src/runtime/cgo -fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/7t/_rsz39554vvgvq2t6b4ztktc0000gn/T/go-build3089540943/b017=/tmp/go-build -gno-record-gcc-switches -fno-common -o $WORK/b017/_cgo_.o $WORK/b017/_cgo_main.o $WORK/b017/_x001.o $WORK/b017/_x002.o $WORK/b017/_x003.o $WORK/b017/_x004.o $WORK/b017/_x005.o $WORK/b017/_x006.o $WORK/b017/_x007.o $WORK/b017/_x008.o $WORK/b017/_x009.o -g -O2 -framework CoreFoundation

I see the same behaviour on both M1 and Intel hosts.

[kubkon]

You need to manually specify include, library and framework search dirs for this to work. In cross-compilation mode, which Zig enters when you explicitly specify the target, no search paths are populated since we don't know where to expect them. Passing the sysroot is one thing, the next should be specifying -I/usr/include, -F/System/Library/Frameworks and -L/usr/lib. Have a look at github.com/kubkon/zig-ios-example to see how this can be done in build.zig. For CGO, I guess you will need to either pass those manually, or put them in some CGO flags, perhaps?

[charleskorn]

Thanks for the tip @kubkon - I had to use -I<sysroot>/usr/include, -F<sysroot>/System/Library/Frameworks and -L<sysroot>/usr/lib, but that was enough to get things working.

Are there any other settings set by default when not specifying -target that I should be using? I also had to add -Wno-expansion-to-defined -Wno-availability -Wno-nullability-completeness to suppress a bunch of warnings that aren't generated when not specifying -target.

[andrewrk]

Duplicate of #1349 and #10660.

[charleskorn]

@andrewrk it looks like there are two issues here:

• the original issue, which was that specifying -target isn't enough, which is a duplicate of ability to link against darwin frameworks (such as CoreFoundation) when cross compiling #1349 and When I cross compile cgo to macos, undefined reference to symbols inside frameworks #10660
• the issue I encountered after fixing that problem, which is that a number of warnings are generated when specifying -target and all the necessary directory arguments, and these warnings aren't emitted if compiling without -target, which seem unrelated to ability to link against darwin frameworks (such as CoreFoundation) when cross compiling #1349 and When I cross compile cgo to macos, undefined reference to symbols inside frameworks #10660 unless I'm missing something

Do you want me to open a separate issue for the second part?

[andrewrk]

Yes please 👍

[kubkon]

@andrewrk it looks like there are two issues here:

• the original issue, which was that specifying -target isn't enough, which is a duplicate of ability to link against darwin frameworks (such as CoreFoundation) when cross compiling #1349 and When I cross compile cgo to macos, undefined reference to symbols inside frameworks #10660
• the issue I encountered after fixing that problem, which is that a number of warnings are generated when specifying -target and all the necessary directory arguments, and these warnings aren't emitted if compiling without -target, which seem unrelated to ability to link against darwin frameworks (such as CoreFoundation) when cross compiling #1349 and When I cross compile cgo to macos, undefined reference to symbols inside frameworks #10660 unless I'm missing something

Do you want me to open a separate issue for the second part?

Is it by any chance related to and fixed by #10568? If so, this fix should land in 0.9.1 I believe - cc'ing @andrewrk to confirm he cherry-picked the commit from the linked PR.

[andrewrk]

Confirmed, it's in the 0.9.x branch as 3542dca.

[charleskorn]

Yes please 👍

Done: #10790