From zero → a working CLion C++ on Windows

Install MSYS2

• There's a download button for the installer executable halfway down the page

Update MSYS2 and install toolchain (in “MSYS2 MSYS” shell)

• Open MSYS2 MSYS (from Start menu), then:

  pacman -Syu            # let it finish; if it tells you to close, do so and reopen MSYS
  pacman -Syu            # run again until fully up to date
  		

• Install the ucrt64 toolchain + build tools:

  pacman -S --needed \
  	mingw-w64-ucrt-x86_64-gcc \
  	mingw-w64-ucrt-x86_64-gdb \
  	mingw-w64-ucrt-x86_64-cmake \
  	mingw-w64-ucrt-x86_64-ninja
  		

  Put the compiler on Windows PATH

  Add ucrt64 bin to your user PATH: C:\msys64\ucrt64\bin (Windows Settings → System → About → Advanced system settings → Environment Variables → User Path → New.)

  Verify in a new PowerShell (or Command Prompt)

  g++ --version
  where g++
  cmake --version
  ninja --version
  gdb --version
  

  You should see the MSYS2 ucrt64 paths, e.g., C:\msys64\ucrt64\bin\g++.exe.

  Install CLion

  • Install CLion normally.

  Configure CLion Toolchain

  The toolchain should already be configured. To verify, you can go to

  CLion → File → Settings → Build, Execution, Deployment → Toolchains
  

  and check:
  • Environment: System (or leave blank)
  • C Compiler: C:\msys64\ucrt64\bin\gcc.exe
  • C++ Compiler: C:\msys64\ucrt64\bin\g++.exe
  • Debugger: C:\msys64\ucrt64\bin\gdb.exe
  • CMake: use CLion’s bundled
  • Generator: Ninja (preferred) → CLion will use ninja.exe on PATH
  (If CLion offers “MinGW” as a preset, point it to C:\msys64\ucrt64 and it will resolve the rest.)

  Create a “Hello C++” project

  • New Project → C++ (Executable) → CMake
  • Keep defaults (uses CMakeLists.txt).
  • CLion creates main.cpp and a simple CMakeLists.txt.
    • The code prints Hello world and a sequence of numbers.
  If you want to write some code of your own, create another project and use the following, simple Hello world program:

  #include <iostream>
  
  using namespace std;
  
  int main() {
  	cout << "Hello world!" << endl;
  }
  

  Build & run

  Click the Build hammer icon (or Build → Build Project). Click Run (green triangle). You should see “Hello, World!” in the Run tool window.