Some cpp properties cannot be exported

Project {
    Product {
        name: "cpp20"
        Export {
            Depends { name: "cpp" }
            cpp.cxxLanguageVersion: "c++20" // this property works fine
            // note: any of the following propties trigger failed qbs parse
            cpp.minimumMacosVersion:"10.15" // broken in Qbs 2.1.x for non MacOS
            cpp.minimumWindowsVersion:"10.0" // broken in Qbs 2.1.x for non Windows
            Properties {
                condition: qbs.toolchain.contains('clang') && !qbs.targetOS.contains("darwin")
                cpp.linkerVariant:"lld" // broken in Qbs 2.1.x for Linux with Clang compiler
            }
        }
    }
    Product {
        name: "HeaderOnly"
        Export {
            Depends { name: "cpp20" }
        }
    }
    StaticLibrary {
        // note: this lib is disabled if broken properties are used
        name: "BrokenLib"
        // note: all three depends are needed to trigger the error
        Depends { name: "cpp20" }
        Depends { name: "HeaderOnly" }
        Depends { name: "Qt.core" }
    }
    Application {
        // note: this app triggers an assert
        Depends { name: "cpp20" }
        Depends { name: "BrokenLib" }
    }
}