Apparently, because of a bug/limitation in Git for Windows, mounting a volume in Docker on Windows is slightly problematic. It took me a while to find the right combination of casing, bracket type and command prefixing to make it work.

The first thing was to prefix the whole command with MSYS_NO_PATHCONV=1, and I had to use the standard round brackets and lowercase $(pwd) with no backslashes or anything like that.

Finally, my docker run invocation looks like this:

MSYS_NO_PATHCONV=1 \
  docker run \
    --rm -v $(pwd):/local \
    openapitools/openapi-generator-cli generate \
      -i http://host.docker.internal:26628/swagger/v1/swagger.json \
      -g typescript-axios \
      -o /local/generated

For clarity - this will run the openapitools/openapi-generator-cli image container with a few extra command switches (-i, -g, -o). Backslashes are there simply to allow me to break the command down over multiple lines and make it more readable. The $(pwd) bit means that Docker will mount my current folder (the one that I’m running the docker run command from in the host OS) under a temporary local folder inside the container. The output of the openapi tool will then put the generated code into the “local/generated” subfolder inside the container (and as a result of that the generated files will end up in the host OS). When the tool finishes with the execution, my actual OS (docker host) folder will have a subfolder called “generated” and all the generated code will be persisted there.

This whole thread contains a few more solutions which didn’t work for me, but maybe you’ll have better luck with them if what was written here doesn’t help you.