Landlab developer install on Windows

[mdpiper]

Building Landlab from source on Windows is trickier than on Linux or macOS. Below are some steps, based on recent experience (originally July 2023, updated July 2024), that should work.

Note that this note is a band-aid: we'll use the information below to update the Developer Install instructions in the Landlab documentation.

Install Anaconda

To set up a Python environment to run Landlab, we use Anaconda. Download Anaconda and install it. This will give you the programs Anaconda Navigator and Anaconda Powershell Prompt.

The installer has only a few steps. In one of them, you're given the option to add Anaconda to the Windows PATH environment variable. Do this! It will allow you to call conda from the Git Bash prompt.

Install Git for Windows

To download, and possibly modify, the Landlab source code, we use Git. Download Git for Windows and install it. This will give you the Git Bash shell.

The installer has many steps. Selecting the defaults are fine for all but one of them: when given the option to add Git for Windows to the Windows path, do it! This will allow you to call git from the Anaconda prompt.

Install Visual Studio Community Edition

Landlab has many parts that are written in C, and we need a C compiler to build them. Download the latest version of Visual Studio Community Edition and install it. We don't need to use Visual Studio directly, but the compiler and linker included with it are used in the Landlab build process.

In the installation, be sure to check the option "Desktop development with C++", which will install the C/C++ compiler. See this help article for more information.

Clone the Landlab repository

Using the Git Bash shell (or an Anaconda Powershell Prompt if you added Anaconda to the Windows path), clone the Landlab repository:

git clone git://github.com/landlab/landlab.git

You may wish to fork Landlab and clone your fork instead.

Also, you'll need an SSH key set up on your machine for communicating with GitHub. See this lesson from CSDMS Ivy for more information.

Create a conda environment

Next, we use conda to create a Python environment with all the dependencies that Landlab needs. Change to the Landlab directory:

cd landlab

and create an environment with:

conda create -n landlab_dev -c conda-forge python pip

Activate the environment:

conda activate landlab_dev

Next, install into the environment the dependencies needed to run Landlab and its example notebooks:

pip install -r requirements.in -r notebooks/requirements.in

Last, to communicate with the compiler and linker included with Visual Studio, install the conda compilers:

conda install -c conda-forge compilers

Build/install Landlab

Build Landlab from source and install it with:

pip install -e .

Once this completes, check that it works by opening a Python interpreter and trying to import landlab.

[nicole-hucke]

Worked great!

The crucial step for me was selecting the "Desktop development with C++". I didn't do it at first, and despite having Visual Studio, I didn't have the C/C++ compiler.

Thank you, Mark 😊

[mdpiper]

Note that I went through the steps above again in July 2024 and made some minor updates.