Cannot run QT macOS app on another MacBook

A cross-platform QT application is built for macOS. This app works if I test this on the same machine. When I create a .dmg file, this also works on my machine. When I test this on another machine, I get the error:

You do not have permission to open the application "MYAPP".

How can I debug this to see what the problem is?

Steps I do to create the .dmg file:

1. Run qmake and make until I have MYAPP.app (release build)

2. binarycreator -c config/config.xml -p packages/ setup_MYAPP

   This creates setup_MYAPP.app

3. codesign -s "Full common name of my Apple Distribution profile" setup_MYAPP.app

   When I provide a meaningless name between quotes it throws an error, so I assume this went fine.

4. hdiutil create -format UDZO -srcfolder setup_MYAPP.app MYAPP.dmg

   This creates MYAPP.dmg, and the installer refuses to run on another macbook.

Alternatively:

1. Run qmake and make until I have MYAPP.app (release build)

2. codesign -s "Full common name of my Apple Distribution profile" MYAPP.app

3. macdeployqt MYAPP.app/ -dmg -codesign="Full common name of my Apple Distribution profile" -appstore-compliant

   This creates MYAPP.dmg, and the app refuses to run on another macbook.

OK, it seems the correct answer is "it's complicated".

I have not succeeded in creating an installer that I can share outside the MAC App Store. Apple has restricted this to the point at which I just give in to bureaucracy and to good looking but really extremely bad documentation.

• Distribution outside the Mac App Store requires notarization since macOS 10.15.5: see https://developer.apple.com/news/?id=04102019a.
• Notarization means signing the code and uploading it to Apple. Apple will perform some magic checks and list it in some internal database.
• Notarization requires a Developer ID certificate: see https://developer.apple.com/documentation/security/notarizing_macos_software_before_distribution/resolving_common_notarization_issues#3087721 This is different from a certificate you need for app development and App Store distribution (Why, Apple, why?)
• To obtain a developer ID certificate you need to fill in the form at https://developer.apple.com/contact/kext, which is the same form used to be able to write kernel extensions. Kernel extensions. (Why, Apple, why?)
• When Apple does not respond to your form submission, you need to poke them a few times. And after they denied your request, you can poke all you want, they likely have set up a vertical classification rule immediately thereafter.

But, should you have been able to get your hands on a precious developer ID certificate, these seem to be the steps to follow to successfully notarize your app:

> security unlock-keychain -p PASSWORD !/Library/Keychains/login.keychain-db
> codesign --timestamp="http://timestamp.apple.com/ts01" --options runtime --verbose=3 --force --deep --sign "NAME OF CERTIFICATE" PATH/TO/APP.app
> xcrun altool -u USER_EMAIL -p APP_SPECIFIC_PASSWORD -notarize-app -t osx --primary-bundle-id INVENT_YOUR_OWN_UNIQUE_ID -f PATH/TO/APP.app

The last run will return another ID, of the form abcdef01-2345-6789-abcd-ef0123456789 and you can use that ID to follow up on your notarization request:

> xcrun altool -u USER_EMAIL -p APP_SPECIFIC_PASSWORD  --notarization-info abcdef01-2345-6789-abcd-ef0123456789

You will also get a mail with a link to the notarization results.

I didn't succeed in getting a go, and I'm giving in. I gave up. The next brave soul to run into this may be saved some time after reading this. Good luck, may you succeed where I failed!