Proper --dist value for local build rpms

Hi all.

I prefer to build mpv, ffmpeg etc from srpm locally. I use ‘build’ tool for that. And now I switched to Tumbleweed from Leap. On the Leap I specified distro with --dist key like ‘sl15.0’, but which one will be optimal for Tumbleweed? If omit this key, than will be used ‘default’, but /usr/lib/build/configs/default.conf is symlink to sl15.5 (using gcc 5!)