When building the nut.pro (with multiple threads) it was possible to have a build failure until the library have not built.
The CONFIG += ordered line solves this problem:
> When using the subdirs template, this option specifies that the directories listed should be processed in the order in which they are given.
https://doc.qt.io/qt-5/qmake-variable-reference.html
Miklós Márton
Hamed Masafi