Windows 上的 QtCreator：找不到 CMAKE_CXX_COMPILER

Question

我有 Visual Studio 2019、CMake 3.18.4、Ninja 1.10.1、Qt 5.15.0、QtCreator 4.13.2，我正在尝试使用 QtCreator 打开一个 Qt/CMake 项目。

我从 CMake 得到这个输出：

2020-12-02T17:04:23 Clang Code Model: Error: The clangbackend process has finished unexpectedly and was restarted.
Running C:\Dev\Libs\Qt-5.15\Tools\CMake_64\bin\cmake.exe -S C:/Dev/test1 -B C:/Users/me/AppData/Local/Temp/QtCreator-GpQBVK/qtc-cmake-tnApaSrE -GNinja "-DCMAKE_BUILD_TYPE:String=Debug" "-DQT_QMAKE_EXECUTABLE:STRING=C:/Dev/Libs/Qt-5.15/5.15.0/msvc2019_64/bin/qmake.exe" "-DCMAKE_PREFIX_PATH:STRING=C:/Dev/Libs/Qt-5.15/5.15.0/msvc2019_64" "-DCMAKE_C_COMPILER:STRING=" "-DCMAKE_CXX_COMPILER:STRING=" in C:\Users\me\AppData\Local\Temp\QtCreator-GpQBVK\qtc-cmake-tnApaSrE.
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
CMake Error at CMakeLists.txt:2 (project):
  No CMAKE_C_COMPILER could be found.

  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:2 (project):
  No CMAKE_CXX_COMPILER could be found.

  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.


-- Configuring incomplete, errors occurred!
See also "C:/Users/me/AppData/Local/Temp/QtCreator-GpQBVK/qtc-cmake-tnApaSrE/CMakeFiles/CMakeOutput.log".
See also "C:/Users/me/AppData/Local/Temp/QtCreator-GpQBVK/qtc-cmake-tnApaSrE/CMakeFiles/CMakeError.log".
CMake process exited with exit code 1.
Elapsed time: 00:01.

无论在 Kit 配置中选择哪个 CMake Tool（我都可以从 CMake 3.18.3 (Qt) 和 System CMake at C:\程序文件\CMake\bin\cmake.exe)

套件配置显示警告标志，虽然不清楚是什么问题：

明显的问题似乎是参数"-DCMAKE_CXX_COMPILER:STRING=" 被传递给CMake（空字符串）。

但是套件中设置了C和C++编译器。

Answer 1

通过Qt维护工具升级解决。