Does the annually updated requirement that apps uploaded to App Store Connect must be built with the latest SDK (i.e. Xcode version) only apply to the main executable or to embedded binaries (e.g. frameworks) also?
SDK minimum requirements for embedded binaries
Thank you for this post, as it serves as a valuable reminder to update all relevant components after the release of a version of Xcode. However, it is important to note that third-party frameworks are not under your direct control. Nevertheless, I strongly recommend downloading the latest version from the third-party provider. This recommendation does not strictly apply to pre-compiled embedded binaries. It primarily pertains to your main application bundle and any app extensions, app clips, widgets, or other components you are building and packaging with it.
When you upload an app to App Store for review, the systems inspect the Info.plist file of your submitted app bundle. Specifically, look at keys injected by Xcode during the build process. As long as your main app executable is built using the required Xcode and SDK versions, even if an embedded pre-compiled framework inside the app was built with an older version of Xcode. Still is important to get the latest to make sure it works well with your app.
If you are using source code frameworks to integrate those frameworks are compiled at the same time as your app. Therefore, they will automatically be built using the latest SDK you are currently using.
If you are dropping in a pre-compiled binary from a vendor, it retains the build environment details from when the vendor compiled it. Make sure those older binaries are functionally compatible with the current OS.
If an older pre-compiled framework uses APIs that Apple has actively banned or removed in the latest OS releases, your app may crash at runtime as deprecated API. Check the warnings in Xcode while testing.
There is a requirements for third-party SDKs to include Privacy Manifests (PrivacyInfo.xcprivacy) and valid signatures, you will have to update it to a newer version that includes one, regardless of what Xcode version it was built with.
Hope this helps. Hope I'm not forgetting anything.
Resources: https://developer.apple.com/app-store/submitting/
Albert WWDR