/axiom:fix-build

Diagnose and fix Xcode build failures using environment-first diagnostics (launches the build-fixer agent).

Command

/axiom:fix-build

What It Does

Checks the build environment before looking at code, preventing "rabbit hole" debugging of ghost issues.

1. Running Builds – Lists running xcodebuild processes and checks who owns them before stopping anything
2. Derived Data – Clears only this project's Derived Data folder, and only for a confirmed stale-build cause
3. Simulator State – Resets only the stuck simulator, leaving other sessions' simulators alone
4. SPM Cache – Validates package resolution state
5. Saved Build Log – Reads the full build log (saved by axbuild, or a plain log file where axbuild isn't available) before deciding whether a rebuild is needed

Before anything destructive, it stops and shows you the cause, the evidence and the exact command, so you can approve it.

When to Use

• You see BUILD FAILED but the error makes no sense
• "No such module" errors appear after switching branches
• "Unable to boot simulator" errors occur
• Xcode is stuck indexing or processing files indefinitely
• You suspect a "ghost in the machine" rather than a code error

Related

• build-fixer – The agent this command launches
• /axiom:optimize-build – Speed up builds after fixing them
• xcode-debugging – The manual skill behind this agent