Qt compilation problems after fresh installation on Ubuntu

I just made a fresh installation of Qt6 on Linux machine running Ubuntu. It was failing to build a default widget application with the error. From the error message it seemed to be some CMake error about not being able to find Qt libraries.

find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Widgets REQUIRED)

Found package configuration file: /home/xxx/Qt/6.0.4/gcc_64/lib/cmake/Qt6/Qt6Config.make but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT FOUND. Reason given by package: Failed to find Qt component "Widgets" config file at""

But the solution was to install some OpenGL libraries. Seems on Ubuntu installation of OpenGL is a requirement for running Qt. The problem went away after I installed libgl1-mesa-dev with the command

apt install libgl1-mesa-dev