I get many similar build errors. Running FC32. I tried 5.x and 6.x and got similar results. Am I missing a dependency?
Thanks!

In file included from compass.h:25,
from compass.cpp:15:
point.h: In member function ‘QPoint& Point3D<_T>:ffsetPoint(const QPoint&, double)’:
point.h:247:10: error: cannot bind non-const lvalue reference of type ‘QPoint&’ to an rvalue of type ‘QPoint’
247 | return QPoint((centerPoint.x() - (int)(x() / ratio)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
248 | (centerPoint.y() - (int)(y() / ratio)));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
point.h: In member function ‘QPoint& Point3D<_T>::inverseOffsetPoint(const QPoint&, double)’:
point.h:254:10: error: cannot bind non-const lvalue reference of type ‘QPoint&’ to an rvalue of type ‘QPoint’
254 | return QPoint(int(rint((centerPoint.x() - x()) * ratio)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
255 | int(rint((centerPoint.y() - y()) * ratio)));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from mapcore.h:38,
from mapcore.cpp:22:
point.h: In member function ‘QPoint& Point3D<_T>:ffsetPoint(const QPoint&, double)’:
point.h:247:10: error: cannot bind non-const lvalue reference of type ‘QPoint&’ to an rvalue of type ‘QPoint’
247 | return QPoint((centerPoint.x() - (int)(x() / ratio)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
248 | (centerPoint.y() - (int)(y() / ratio)));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
point.h: In member function ‘QPoint& Point3D<_T>::inverseOffsetPoint(const QPoint&, double)’:
point.h:254:10: error: cannot bind non-const lvalue reference of type ‘QPoint&’ to an rvalue of type ‘QPoint’
254 | return QPoint(int(rint((centerPoint.x() - x()) * ratio)),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
255 | int(rint((centerPoint.y() - y()) * ratio)));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~