Problem with mingw64-x86_64-qt5ct

[David R. Bergstein via Cygwin-apps]

I have been trying to run the following command from my cygwin environment:
/usr/x86_64-w64-mingw32/sys-root/mingw/bin/qt5ct.exe

This results in a dialog saying that the following library could not be 
found:  libqt5ct-style.so

I did a search for this file both here and online and could not find 
it.  Is there a solution for this issue?

Sincerely,

David R. Bergstein