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macoslinkerframeworksmac-catalyst

Mac Catalyst build fails with "building for Mac Catalyst-x86_64 but attempting to link with file built for Mac Catalyst-arm64"

After updating to Xcode 12.2, my project started failing to compile because of Apple Silicon-related linking errors. I seem to have most of them fixed, but one sub-project that builds a statically-linked framework is giving me problems. And yet a sibling sub-project with apparently identical build settings doesn't.

During linking, I get this warning about the one framework:

ld: warning: ignoring file ...Build/Products/Debug-maccatalyst/TCSiOSC.framework/TCSiOSC, building for Mac Catalyst-x86_64 but attempting to link with file built for Mac Catalyst-arm64

I'm building on an Intel Mac, to boot (so "build active architecture only" is not a factor). I can't find any build setting that would address this problem, and a Web search turns up no hits on this exact error. Any ideas appreciated!

Solution

  • I consulted Apple for this one, and their engineer recommended some things:

    1. Turn any Swift sub-projects into Swift packages, not embedded Xcode projects. So, I deleted one library's Xcode project from the parent project, and dragged its top-level directory into the parent project to include it as a Swift package. Now... this particular sub-project (SQLite.swift) already had a Swift package defined. I haven't generated a Swift package myself before, so I can't help with that. Also, don’t forget to add it to the Frameworks, Libraries, and Embedded Content list on the app’s target.

    2. Go into your project's build settings and delete the "Supported platforms" setting. If you click on the "levels" button above the build-settings list, you can see where each setting is coming from. "Supported platforms" should be non-bold. Highlight the line and press Delete if it's bold. Then go into your target and do the same thing: delete "Supported platforms."

    3. Set the Base SDK at your project (top) level to iOS; this is a must. Delete it from the target level, so it inherits from the project; I don't know if this holds true for multiple kinds of targets or all projects, but it's working for me.

    4. Remove the VALID_ARCHS build setting from all targets, if it's present. That setting is deprecated.

    The "build active architecture" setting doesn't make any difference after these changes in my case. The project now builds and runs under Catalyst just fine.