How do I diagnose and fix 'Provisioning profile doesn't include signing certificate' in Swift/Xcode?

When developing an iOS application in Xcode, you might encounter the error message "Provisioning profile doesn't include signing certificate." This error typically indicates that there is a mismatch between the provisioning profile and your signing certificate, which is essential for app distribution. Here’s how to diagnose and fix this issue.

Diagnosing the Issue

1. **Check Your Certificates**: Open Keychain Access on your Mac and verify that the correct signing certificates are installed. You should have the necessary certificates for development and distribution. Ensure that they are marked as valid and trusted.

2. **Review Your Provisioning Profiles**: Go to the Apple Developer portal and check your provisioning profiles. Ensure that the correct profiles are set up for the correct bundle identifier and have included the necessary signing certificates.

Fixing the Issue

1. **Regenerate Provisioning Profiles**: If you have updated or changed your certificates, regenerate your provisioning profiles. You can do this through the Apple Developer portal by deleting the old profile and creating a new one linked to the updated certificate.

2. **Update Xcode Settings**: In Xcode, navigate to Project Settings > Signing & Capabilities. Ensure that the correct team is selected, and choose "Automatically manage signing" if you want Xcode to handle profiles and certificates automatically.

3. **Clean Build Folder**: Sometimes Xcode caches build data can cause issues. Go to the menu bar and select Product > Clean Build Folder to clear the cached data.

Final Steps

After following the above steps, try to build your project again. If the issue persists, double-check the configurations in both Xcode and the Apple Developer portal to ensure everything is correctly set up.