Xcode Debugging
Environment-first diagnostics for mysterious Xcode issues. Prevents 30+ minute rabbit holes by checking build environment before debugging code.
When to use: BUILD FAILED, test crashes, simulator hangs, stale builds, zombie xcodebuild processes, "Unable to boot simulator", "No such module" after SPM changes, mysterious test failures
Key Features
- Mandatory environment checks (Derived Data, processes, simulators)
- Quick fix workflows for common issues
- Decision tree for diagnosing problems
- Crash log analysis patterns
- Time cost transparency (prevents rabbit holes)
Philosophy: 80% of "mysterious" Xcode issues are environment problems, not code bugs. Check environment BEFORE debugging code.
TDD Tested: 6 refinements from pressure testing with Superpowers framework
Example Prompts
These are real questions developers ask that this skill answers:
"My build is failing with 'BUILD FAILED' but no error details. I haven't changed anything." → Shows environment-first diagnostics: clean Derived Data, check simulator states, identify zombie processes
"Tests passed yesterday with no code changes, but now they're failing." → Explains stale Derived Data and intermittent failures, shows the 2-5 minute fix
"My app builds fine but it's running the old code from before my changes." → Demonstrates that Derived Data caches old builds, shows how deletion forces a clean rebuild
"The simulator says 'Unable to boot simulator' and I can't run tests." → Covers simulator state diagnosis with simctl and safe recovery patterns
"I'm getting 'No such module: SomePackage' errors after updating SPM dependencies." → Explains SPM caching issues and the clean Derived Data workflow