How to fix CMake 'Failed to find Qt component "Core5Compat"' on Ubuntu

Problem:

When trying to compile your CMake project, you see an error message such as

CMake Error at cMake/FreeCAD_Helpers/SetupQt.cmake:33 (find_package):
  Found package configuration file:

    /usr/lib/x86_64-linux-gnu/cmake/Qt6/Qt6Config.cmake

  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 "Core5Compat".

  Expected Config file at
  "/usr/lib/x86_64-linux-gnu/cmake/Qt6Core5Compat/Qt6Core5CompatConfig.cmake"
  does NOT exist

  

Call Stack (most recent call first):
  CMakeLists.txt:82 (include)

Solution

sudo apt -y install libqt6core5compat6-dev

Tested on Ubuntu 22.04