Updating msvc toolchain leaves you with "unloadable" project

Running C:\Qt\Tools\CMake_64\bin\cmake.exe -S C:/dev/src/qc -B C:/dev/build/qc-qc-Desktop_Qt_6_0_2_MSVC2019_64bit-Debug in C:\dev\build\qc-qc-Desktop_Qt_6_0_2_MSVC2019_64bit-Debug.
-- Configuring incomplete, errors occurred!
See also "C:/dev/build/qc-qc-Desktop_Qt_6_0_2_MSVC2019_64bit-Debug/CMakeFiles/CMakeOutput.log".
See also "C:/dev/build/qc-qc-Desktop_Qt_6_0_2_MSVC2019_64bit-Debug/CMakeFiles/CMakeError.log".
CMake Error at CMakeLists.txt:18 (project):
 The CMAKE_C_COMPILER:

C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Tools/MSVC/14.28.29910/bin/HostX64/x64/cl.exe

is not a full path to an existing compiler tool.

Tell CMake where to find the compiler by setting either the environment
 variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
 the compiler, or to the compiler name if it is in the PATH.


CMake Error at CMakeLists.txt:18 (project):
 The CMAKE_CXX_COMPILER:

C:/Program Files (x86)/Microsoft Visual Studio/2019/Professional/VC/Tools/MSVC/14.28.29910/bin/HostX64/x64/cl.exe

is not a full path to an existing compiler tool.

Tell CMake where to find the compiler by setting either the environment
 variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
 to the compiler, or to the compiler name if it is in the PATH.


CMake process exited with exit code 1.
Elapsed time: 00:00.