Xcode Package.swift Misidentification Diagnosis

Extracted: 2026-02-11 Context: iOS app builds succeed but simulator doesn't launch

Problem

When a project directory contains both Package.swift and .xcodeproj, Xcode may open the directory as a Swift Package instead of the Xcode project. This causes:

• Build succeeds (the library target in Package.swift compiles)
• Simulator doesn't launch (no app target exists in the package)
• No obvious error messages

Diagnosis

Check DerivedData info.plist to see what Xcode actually opened:

# List recent DerivedData entries
ls -lt ~/Library/Developer/Xcode/DerivedData/ | head -5

# Check WorkspacePath
plutil -p ~/Library/Developer/Xcode/DerivedData/<project-dir>/info.plist

Key indicator: WorkspacePath points to the directory (e.g., /path/to/project) instead of the .xcodeproj file (e.g., /path/to/project/Project.xcodeproj).

Also check what was actually built:

ls ~/Library/Developer/Xcode/DerivedData/<project-dir>/Build/Products/Debug-iphonesimulator/

If you see only .o / .swiftmodule files (no .app), the package was built instead of the app.

Solution

Open the .xcodeproj file directly:

open /path/to/project/Project.xcodeproj

Do NOT open the directory with xed . or double-click when both Package.swift and .xcodeproj exist.

When to Use

• iOS app "builds but doesn't run" on simulator
• Build products contain only library artifacts, not .app
• Project has both Package.swift and .xcodeproj at the root