In order to work on addons-frontend on Windows (10), you must:
Note 1: it is important to not have Node.js or Yarn installed on your main Windows system because these tools are available in WSL and can conflict with the tools installed in WSL itself.
Note 2: it might work with WSL 2 or a different distribution but it is not the recommended setup as we cannot test all the different combinations.
Next, open Ubuntu and install Node.js and Yarn (this is pretty standard but those commands have been tested when writing this guide):
$ curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
$ curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
$ echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
$ sudo apt update
$ sudo apt-get install -y nodejs gcc g++ make yarn
Your (sub-)system is now ready and you can follow the common instructions to get started.
This can be caused by Yarn being installed on the main Windows system or a cache issue. Make sure to use the yarn CLI installed as described in the previous section. You can also try to delete your yarn cache:
$ rm -r ~/.cache/yarn/
When such an error occurs, it is also best to remove the node_modules/ folder before re-running yarn.