Command CodeSign failed with a nonzero exit code

One of the files in your project must have a resource fork attached to it. Please check the following reference:

Technical Q&A QA1940 Code signing fails with error 'resource fork, Finder information, or similar detritus not allowed' https://developer.apple.com/library/archive/qa/qa1940/_index.html#//apple_ref/doc/uid/DTS40017555

Thanks for your reply, but unfortunately, it doesn't seem to do the job.

The error in full that I am getting this evening is:

CodeSign /Users/user/Documents/GitHub/MyApp/MyApp/DerivedData/MyApp/Build/Intermediates.noindex/ArchiveIntermediates/MyApp/InstallationBuildProductsLocation/Applications/MyApp.app (in target 'MyApp' from project 'MyApp')
    cd /Users/user/Documents/GitHub/MyApp/MyApp
    
    Signing Identity:     "Apple Development: My Name (REDACTED)"
    Provisioning Profile: "iOS Team Provisioning Profile: REDACTED"
                          (REDACTED)
    
    /usr/bin/codesign --force --sign {REDACTED} --entitlements /Users/user/Documents/GitHub/MyApp/MyApp/DerivedData/MyApp/Build/Intermediates.noindex/ArchiveIntermediates/MyApp/IntermediateBuildFilesPath/MyApp.build/Release-iphoneos/MyApp.build/MyApp.app.xcent --generate-entitlement-der /Users/user/Documents/GitHub/MyApp/MyApp/DerivedData/MyApp/Build/Intermediates.noindex/ArchiveIntermediates/MyApp/InstallationBuildProductsLocation/Applications/MyApp.app

/Users/user/Documents/GitHub/MyApp/MyApp/DerivedData/MyApp/Build/Intermediates.noindex/ArchiveIntermediates/MyApp/InstallationBuildProductsLocation/Applications/MyApp.app: resource fork, Finder information, or similar detritus not allowed
Command CodeSign failed with a nonzero exit code

When I run:

xattr -lr MyApp.app

I get the following output:

MyApp.app/Base.lproj/Main.storyboardc: com.apple.FinderInfo: 
MyApp.app/Base.lproj/Main.storyboardc: com.apple.fileprovider.fpfs#P: 
MyApp.app/Base.lproj/LaunchScreen.storyboardc: com.apple.FinderInfo: 
MyApp.app/Base.lproj/LaunchScreen.storyboardc: com.apple.fileprovider.fpfs#P: 
MyApp.app: com.apple.FinderInfo: 
MyApp.app: com.apple.fileprovider.fpfs#P:

When I run:

xattr -cr MyApp.app

It does something, but I am still presented with the same error.

Now to complicate things, even though I get the same error, the Applications directory isn't being generated.

I can't understand why there would be forks in the StoryBoards, I do have some RSS feeds and links out.

You'll have to clean your files before building and signing your app, not after.

I have tried everything suggested from the post by DTS engineer, but I still can't get it working.

I am now getting something slightly different:

Command CodeSign failed with a nonzero exit code

I suggest you submit a code-level support request so that I can take a look at your Xcode project, view your signing logs, etc. Once I have that information, we can continue the discussion here in the forums. When you create the request, indicate that you were referred by someone at Apple and make sure to include a link to this thread.