Minimum required version of macOS

[René J.V. Bertin]

> Frameworks 101 builds fine with 10.15 except one line 
>in kguiaddons.

What's the minimum required Qt version for KF5 101? If you're using that Qt version (i.e. not a newer one) and get a build failure (what line?) you should be filing a bug report.

>This problem also leads to crashes of nightly builds when installed on 10.15 or earlier.
>Can we at least specify a minimum required version of macOS or make sure that Frameworks builds and runs on older versions like macOS 10.15?

Cc'ing this to kde-frameworks-devel as that's the appropriate ML.

FYI, my own MBP which is still perfectly useable for most daily tasks with its 2.6Ghz i7 is from 2011 and cannot (officially) be upgraded beyond 10.13 . I *think* Qt 5.15 is supported there but am not even certain.

R.