Installing CLion

Please note that these instructions only work when using a Ninja generator from a Windows or Linux operating system.

You will also need to have Visual Studio installed on windows.

If you haven’t installed CLion yet do that now, CLion can be installed from here.

Opening CLion

The first time you build from CLion, you will most likely need to launch it from a terminal or command line to make sure you have access to all the relevant tools.

  • On Linux,

    1. Open any terminal

    2. Run conda activate mantid-developer

    3. Then launch CLion from this terminal with <CLION_INSTALL>/bin/

  • On Windows,

    1. Using your search bar, open the x64 Native Tools Command Prompt for VS 2019 command prompt

    2. Run conda activate mantid-developer

    3. Then launch CLion with <CLION_INSTALL>/bin/clion.bat

If you get errors about being unable to compile a ‘simple test program’, then doing the above should fix your issue.

Setup for a CLion Build

Follow these instructions when the CLion IDE has opened:

To set up your toolchain:

  1. Navigate to File > Settings > Build, Execution, Deployment > Toolchains

  2. Create a new System toolchain using the + icon and call it Default

  3. Edit the CMake field to point to your conda installed cmake

    • On Linux: /path/to/mambaforge/envs/mantid-developer/bin/cmake

    • On Windows: /path/to/mambaforge/envs/mantid-developer/Library/bin/cmake.exe

  4. Edit the Build Tool field to point to your conda installed ninja

    • On Linux: /path/to/mambaforge/envs/mantid-developer/bin/ninja

    • On Windows: /path/to/mambaforge/envs/mantid-developer/Library/bin/ninja.exe

  5. For the C Compiler and C++ Compiler fields,

    • On Linux: choose Let CMake detect

    • On Windows: direct them both at the same cl.exe in your Visual Studio installation, e.g. C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.29.30133/bin/Hostx64/x64/cl.exe

To set up CMake:

  1. Navigate to File > Settings > Build, Execution, Deployment > CMake

  2. Edit the Build type field by either selecting an option, or typing in a string

    • On Linux: Debug

    • On Windows: DebugWithRelRuntime

  3. Set your Toolchain to be the Default toolchain that you just created

  4. Set your generator to be Ninja

  5. Edit your Cmake options to be

    • On Linux: --preset=linux

    • On Windows: --preset=win-ninja

  6. Set the build directory to the build directory if it is not the default (you’ll need to use the full path if its outside the source directory)

  7. The configurations drop-down at the top should show all of the build targets. If not, the CMake project is probably not loaded. Go to File > Reload CMake Project. The configurations should be populated

Building with CLion

  • To build all targets, navigate to Build > Build All in 'Debug'. Check that the build command displayed in the Messages window is running the correct cmake executable from your conda installation.

  • To build a specific target, select it in the configurations drop-down menu and click the hammer icon next to it.

If this fails, you may need to open CLion from a terminal with your conda environment activated.

It is also useful to have your terminals in CLion to run with this environment:

  1. In your home directory create a file named .clionrc and open in your favourite text editor, adding these lines:

    source ~/.bashrc
    source ~/mambaforge/bin/activate mantid-developer
  2. Start CLion using the above steps

  3. Navigate to File > Settings > Tools > Terminal

  4. To the end of the Shell path option, add --rcfile ~/.clionrc

Debugging with CLion

To debug workbench, you’ll need to edit the workbench CMake Application configuration.

  1. Set the executable to be the python.exe in your conda installation

    • On Linux: /path/to/mambaforge/envs/mantid-developer/bin/python.exe

    • On Windows: /path/to/mambaforge/envs/mantid-developer/python.exe

  2. Set the program arguments

    • On Linux: workbench --single-process

    • On Windows: workbench-script.pyw --single-process

  3. Set the working directory to be the full path to your build/bin directory

The --single-process flag is necessary for debugging. See the Running Workbench documentation for more information.

You should now be able to set breakpoints and start debugging by clicking the bug icon.


macOS developers will see the warning from Qt in the terminal:

An OpenGL surfcace format was requested that is either not version 3.2 or higher or a not Core Profile. Chromium on macOS will fall back to software rendering in this case. Hardware acceleration and features such as WebGL will not be available.

It can be safely ignored but is present as a reminder of some deprecated OpenGL functionality being used. It is only visible to developers and the spelling mistake is real.