I have an older Mac mini (mid 2011) which runs macOS 10.11, 10.12 and 10.13. It did not allow me to install macOS 10.14, so I had to order another (used) Mac mini (late 2012) that now runs macOS 10.13 and macOS 10.14 in separate partitions. Because running
$ hdiutil create -size <size>b <.dmg-file> -srcfolder <directory> -ov -format UDBZ
on macOS 10.14 creates a dmg file that can't be opened on macOS 10.11, we need to bundle our applications on macOS 10.11.
I've tried to create an image of the macOS 10.11 partition on the old Mac mini and restore it on the new one - it failed and reported about not having enough permissions.
I've tried several ways to download the installer of macOS 10.11, e.g. using the link on https://support.apple.com/en-us/HT206886, but the App Store on the new Mac mini always tells me that my machine is too new, and the App Store on the old Mac mini simply tells me that macOS 10.11.6 "cannot be installed on this computer".
Is there a way to install macOS 10.11 on my newer Mac mini?