Develop with Conda on Windows

Install Visual Studio 2022 Community Edition

  • When asked about installation workloads choose Desktop development with C++

  • Under the “Installation details” section verify that the following are checked:

    • Windows Universal CRT SDK

    • The latest Windows 10 SDK

    • MSVC v142 - VS 2019 C++ x64/x86 build tools

  • If your machine has less than 32GB of memory Mantid may not build. If you have problems change the maximum number of parallel project builds to 1 in Visual Studio in Tools -> Options -> Projects and Solutions -> Build And Run.

Install Git

  • Install the latest version of Git, and ensure git bash was installed and the git executable location was added to your PATH, if you didn’t do this as part of your installation you can do this manually.

  • We no longer need Git LFS as conda handles the dependencies that used to be in the third party directory.

Turn off Python association in Windows

  • Because of the way Windows associates Python files with it’s Windows Store version of python we need to turn off this association. If you don’t turn this off you will have issues when running the pre-commit framework.

  • Navigate to your Settings -> Manage App Execution Aliases, and turn off all Python Aliases.

Clone the mantid source code

  • Important: If you have any existing non-conda mantid development environments, do not re-use the source and build directories for your conda environment. We recommend that you clone a new instance of the source and keep separate build directories to avoid any cmake configuration problems.

  • Clone the mantid source code by either:

    • Using git bash and cloning the codebase by calling git clone git@github.com:mantidproject/mantid.git in the directory you want the code to clone to. This sets you up with accessing the remote repository via SSH so make sure to setup git properly using this startup guide and ensure your ssh key is setup using this guide to Github with SSH.

    • Or using GitKraken.

Install Mambaforge

  • Choose the latest version of Mambaforge-Windows-x86_64.exe

  • Run your downloaded Mambaforge-Windows-x86_64.exe and work through the installer until it finishes. In order to make it easier later on, check the box that adds Conda to your path.

Setup the mantid conda environment

Open a terminal or powershell with conda enabled. Here are two ways to do this:

  • Open an Anaconda prompt (Mambaforge).

  • Add the path of your Mambaforge installation to your system path, if you didn’t do it during installation (Follow the answers in the FAQ). Then you can use conda from the Command Prompt and Powershell.

Create a Conda environment and install the mantid-developer Conda metapackage by following the steps below:

  • First create and activate a new conda environment. Here we have named it mantid-developer for consistency with the rest of the developer documentation but you are free to choose any name.

    mamba create -n mantid-developer
mamba activate mantid-developer

  • Install the mantid-developer Conda metapackage from the mantid Conda channel. You will normally want the nightly version.

    mamba install -c mantid/label/nightly mantid-developer

Configure CMake and generate build files

  • You can configure CMake using an MS Visual Studio or Ninja generator. Choose one of the following:

    • For MS Visual Studio, use the terminal or powershell prompt from the last step.

    • For Ninja, open the x64 Native Tools Command Prompt for VS 2019 or x64 Native Tools Command Prompt for VS 2022 from your search bar.

  • Navigate to your mantid source directory.

  • If not already activated in the previous step, run conda activate mantid-developer to activate your conda environment.

  • If you want your build directory inside your source directory, run either:

    • cmake --preset=win-vs for configuring with Visual Studio 2022, or

    • cmake --preset=win-vs-2019 for configuring with Visual Studio 2019, or

    • cmake --preset=win-ninja for configuring with Ninja.

  • Alternatively, if you want to specify a different build directory, run either:

    • cmake --preset=win-vs -B {BUILD_DIR}, or

    • cmake --preset=win-vs-2019  -B {BUILD_DIR}, or

    • cmake --preset=win-ninja -B {BUILD_DIR}

Compile and Build using MS Visual Studio

  • Open visual studio with visual-studio.bat, which is found in the build folder, and then click build.

  • It’s not possible to compile in Debug on Windows with conda libraries, however Release, RelWithDebInfo, and DebugWithRelRuntime for Debugging will compile fine.

  • Once in visual studio, the correct target to use as a startup project in visual studio is workbench, not MantidWorkbench. You can then press F5 to start workbench.

Compile and Build using Ninja

  • From the command line:

    • Navigate to the build directory using the x64 Native Tools Command Prompt for VS 2019 or x64 Native Tools Command Prompt for VS 2022 from the previous step.

    • To build Mantid Workbench use: ninja

    • To build the unit tests use: ninja AllTests

  • In Visual Studio:

    • Open Visual Studio with visual-studio_ninja.bat, which is found in the build folder

    • Select “win-ninja” from the Configuration dropdown at the top of the screen

    • Select “Switch between solutions and available views” in the Solution Explorer and click on “CMake Targets View”

    • It is recommended that the “When cache is out of date” option is set to “Never run configure step automatically” in Tools->Options->CMake

Building and debugging with CLion

Please follow the Windows related instructions on this page.

CMake Conda variables

The CONDA_BUILD parameter is used to customise our installation, which is required when we are using the conda-build tool to build and package Mantid. This option can be passed to CMake on the command line using -DCONDA_BUILD=True.