fix

name	fix
description	Diagnose and fix an error from a build failure, stack trace, or error message
disable-model-invocation	true
argument-hint	<error message, stack trace, or description>

Fix

Diagnose and fix the provided error. This could be a build error, runtime crash, test failure, or a description of unexpected behavior.

Input: $ARGUMENTS

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Step 1: Parse the Error

Analyze the input to determine:

• Error type: Build error, runtime crash (stack trace), test failure, or described behavior
• Location: File path(s) and line number(s) referenced in the error
• Root cause clues: Error message, compiler error, exception type

If the input is a description rather than an error output, search the codebase for the relevant code.

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Step 2: Locate the Source

Read the file(s) referenced in the error. If no file is referenced:

• Search for relevant class/function names from the error message
• Check recent changes (git diff main) that may have introduced the issue

Read enough surrounding context to understand the code's intent — not just the failing line.

---

Step 3: Diagnose

Identify the root cause. Common categories:

Build Errors

• Missing imports or dependencies
• Type mismatches or incorrect generics
• Unresolved references (renamed/moved symbols)
• Sendable conformance violations
• @MainActor isolation mismatches
• Missing Hashable/Codable conformance on TrapezioScreen
• Missing Equatable conformance on TrapezioState

Runtime Crashes

• Force unwrap on nil value
• fatalError in unoverridden doWork(params:) or createObservable(params:)
• Actor isolation violations
• Concurrency issues (data races)

Test Failures

• Assertion mismatches (expected vs actual)
• Missing or incorrect Fakes
• Async timing (state not updated before assertion — missing Task.sleep)
• AsyncStream.makeStream() synchronization issues

Logic Bugs

• Incorrect conditional or operator
• State not updated correctly via update { }
• Event not handled in switch block
• Navigation called with wrong screen/args
• strataLaunch capturing stale state

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Step 4: Fix

Apply the minimal fix that resolves the root cause. Do not refactor surrounding code or make unrelated improvements.

If the fix requires changes across multiple files (e.g., a renamed protocol), update all affected files.

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Step 5: Verify

After applying the fix:

• If it was a build error: Run cd MESA && swift build to verify it compiles
• If it was a test failure: Run cd MESA && swift test --parallel to verify it passes
• If it was a Counter app error: Run xcodebuild build -scheme Counter -destination 'platform=iOS Simulator,name=iPhone 16'
• If it was a runtime crash or logic bug: Verify the fix compiles and explain what changed

Report what was wrong and what was changed.