working-directory:

[kousu]

I would like to use working-directory: to make my WSL tests test inside of WSL, not over the Windows mountpoint. The Windows virtual mountpoints in /mnt/c, /mnt/d, /c/, /d/, are slow (spinalcordtoolbox/spinalcordtoolbox#3575) and glitchy (spinalcordtoolbox/spinalcordtoolbox#3571).

  windows-wsl-ubuntu-20_04:
    name: WSL [Ubuntu 20.04]
    runs-on: windows-2019
    defaults:
      run:
        shell: wsl-bash {0} # https://github.com/marketplace/actions/setup-wsl#default-shell
        working-directory: /c/Users/runneradmin
    steps:
    - uses: Vampire/setup-wsl@v1
      with:
        distribution: Ubuntu-20.04
    - name: Dependencies
      run: |
        pwd # DEBUG
        sudo apt update && sudo DEBIAN_FRONTEND=noninteractive apt install -y gcc git curl mesa-utils

but as soon as my run gets to "Dependencies" it gives

Error: The directory name is invalid.

because working-directory: effectively runs cd on the outer system before calling shell: .

But if I use Windows-style paths:

        working-directory: C:\Users\runneradmin

it runs, but then pwd is /mnt/c/Users/runneradmin which is what I wanted to avoid in the first place.

If I simply do

  windows-wsl-ubuntu-20_04:
    name: WSL [Ubuntu 20.04]
    runs-on: windows-2019
    defaults:
      run:
        shell: wsl-bash {0} # https://github.com/marketplace/actions/setup-wsl#default-shell
    steps:
    - uses: Vampire/setup-wsl@v1
      with:
        distribution: Ubuntu-20.04
    - name: Dependencies
      run: |
        cd
        pwd # DEBUG
        sudo apt update && sudo DEBIAN_FRONTEND=noninteractive apt install -y gcc git curl mesa-utils

on the other hand, then pwd is /root, which works for me and is what I want, but then I need to paste that cd in to every step. Plus actions/checkout puts my repo in the Windows part, so I need to add:

    - uses: actions/checkout@v2
    - name: Copy from $GITHUB_WORKSPACE to ~
      run: cp -rp ../spinalcordtoolbox ~/spinalcordtoolbox

Any ideas on if there a way to tell wsl-bash to respect default: working-directory: ...? Or maybe a separate default: wsl-working-directory: ...?

[Vampire]

wsl-bash does respect working-directory.
C:\Users\runneradmin is just not the home directory within WSL.
To use working-directory for your use-case you would have to find out which Windows path corresponds to the WSL path where you want to be and use that.

But you can also easily use the wsl-shell-command input for your use-case.
Just set it to bash -c "cd && bash --noprofile --norc -euo pipefail "\ (the final slash is not a typo) or bash -c "cd && bash --noprofile --norc -euo pipefail '{0}'" and your wsl-bash will always start in the WSL home directory.
I added the latter variant to the examples for the wsl-shell-command input.