atch App stuck indefinitely on "Installing..." when installing debug build via iOS Watch app (Latest OS & Xcode)

Hi everyone,

I am developing an iOS companion app with an integrated watchOS component (a golf swing tracking tool using CoreMotion).

I have run into an issue where the watchOS app gets stuck indefinitely in the "Installing..." state and never finishes installing on the physical Apple Watch.

Environment (All on latest public releases):

• Xcode Version: Latest release (Xcode 18.x)
• macOS Version: Latest release (macOS Sequoia / latest version)
• iOS Version: Latest release (iOS 20.x)
• watchOS Version: Latest release (watchOS 13.x on Apple Watch Ultra 2)
• Deployment Target: Matched to latest minimum deployments
• Signing: "Automatically manage signing" enabled with an active Apple Developer Program account

Steps to Reproduce:

1. Connect the iPhone to the Mac via a physical cable.
2. Select the iOS target in Xcode and successfully run/install the companion app onto the iPhone.
3. Launch the stock Watch app on the paired iPhone.
4. Scroll down to the "Available Apps" section, locate the development app, and tap "Install".
5. The circular progress indicator starts spinning with the status "Installing...", but it remains in this state indefinitely (waited over 2 hours) without ever completing, timing out, or surfacing an error alert on either the iPhone or the Apple Watch.

Troubleshooting Already Verified:

1. Bundle ID Hierarchy:
   • iOS App: com.company.appname
   • Watch App: com.company.appname.watchkitapp
   • Both targets share the exact same Development Team, signing certificate, and provisioning profiles.
2. Developer Mode:
   • Explicitly enabled and rebooted on the Apple Watch (Settings -> Privacy & Security -> Developer Mode).
   • Also verified as enabled on the host iPhone.
3. Connectivity & Cache:
   • Cleared Xcode DerivedData (rm -rf ~/Library/Developer/Xcode/DerivedData).
   • Performed hard reboots on both the iPhone and the Apple Watch to terminate any hung background sync daemons (installd / CoreDevice).
   • Ensured both devices and the Mac are on the same Wi-Fi network with Bluetooth turned on.

Questions:

1. Under the current CoreDevice architecture, is installing local debug builds via the iPhone's stock Watch app still supported, or does it silently fail because the physical Apple Watch's UDID is not directly provisioned during an iOS-only build?
2. Which subsystem in macOS Console.app (e.g., com.apple.dt.CoreDevice, com.apple.StreamingExtractor, or installd) is best for tracking the exact error/timeout code when the watch installation hangs?
3. What is the currently recommended workflow to deploy and debug a paired watchOS target directly onto physical hardware?

Any insights from the team or community would be greatly appreciated!