Swift code in a library failed to compile

iOS / Xcode · last reviewed 2026-11-10

The error looks like this

[RUN_FASTLANE] ▸ The following build commands failed:
[RUN_FASTLANE] ▸ CompileSwift normal arm64 (in target 'ExpoModulesCore' from project 'Pods')
[RUN_FASTLANE] ▸ (4 failures)

Why it happens

A pod was written for a different Xcode / iOS SDK than the one building it — typically the library is newer than your Xcode, or older than it.

How to fix it

Find the first line containing "error:" above this — it names the file and the library.
Update that library to a version that supports your Xcode, or update Xcode to the version the library needs (Expo: each SDK lists its required Xcode).
Then: cd ios && pod install --repo-update, clean the build folder, and build again.

Not sure this is your error? Let ReleaseMedic read the whole log

Build logs are long and the last line is rarely the real cause. ReleaseMedic finds the first real error, explains it and gives the steps — free, and the log never leaves your computer.

$ npx releasemedic log build.log

Or pipe a build straight in: cd android && ./gradlew bundleRelease 2>&1 | npx releasemedic log -

Catch it before you build

Most release errors come from project settings you can check in seconds — signing, SDK levels, privacy manifests, permissions, push and login setup.

$ npx releasemedic