watchOS app embedded in Watch/ instead of PlugIns/ — fails on Xcode 26

Summary

When a watchOS app target is declared as a dependency with embed: true, XcodeGen generates a "Embed Watch Content" copy phase using dstSubfolderSpec = 16 and dstPath = "$(CONTENTS_FOLDER_PATH)/Watch".

Starting with Xcode 26, this causes an install failure because watchOS apps must be embedded in the parent app's PlugIns/ directory (dstSubfolderSpec = 13, empty dstPath), the same as foundation extensions.

Error

MyWatchApp.app is a Foundation extension and must be embedded in the parent app bundle's
PlugIns directory, but is embedded in the parent app bundle's Watch directory.

project.yml

targets:
  MyApp:
    type: application
    platform: iOS
    dependencies:
      - target: MyWatch Watch App
        embed: true

  MyWatch Watch App:
    type: application
    platform: watchOS

Expected

The generated copy phase should use:

dstPath = "";
dstSubfolderSpec = 13;

Actual

The generated copy phase uses:

dstPath = "$(CONTENTS_FOLDER_PATH)/Watch";
dstSubfolderSpec = 16;

Workaround

Post-gen sed patch in project.yml:

options:
  postGenCommand: sed -i '' -e 's|dstPath = "$(CONTENTS_FOLDER_PATH)/Watch";|dstPath = "";|' -e 's|dstSubfolderSpec = 16;|dstSubfolderSpec = 13;|' MyApp.xcodeproj/project.pbxproj

Environment

• XcodeGen 2.45.3
• Xcode 26.4 (17E192)
• macOS 26.3.1

Start with the dependency embedding logic that handles a watchOS application declared with embed: true, using the project.yml example and generated MyApp.xcodeproj/project.pbxproj as the reproduction. Verify that the generated copy phase uses an empty dstPath and dstSubfolderSpec = 13, then confirm the project installs successfully with Xcode 26.