I am trying to run some python script using external resource in terraform on github actions workflow but it throws Python3 not found error.

This works fine from local linux system.

module.tf

data "external" "debug_path" {
  program = ["/bin/bash", "-c", "echo \"{\\\"PATH\\\": \\\"$PATH\\\", \\\"PYTHON\\\": \\\"$(which python3)\\\"}\""]
}

output "debug_info" {
  value = data.external.debug_path.result
}

My terragrunt.hcl

include "root" {
  path = find_in_parent_folders()
}

terraform {
  source = "."
}

When I do terragrunt plan from local system, I get:

  + debug_info = {
      + PATH   = "/home/myuser/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/wsl/lib:/mnt/c/Windows/system32:/mnt/c/Windows:/mnt/c/Windows/System32/Wbem:/mnt/c/Windows/System32/WindowsPowerShell/v1.0/:/mnt/c/Windows/System32/OpenSSH/:/mnt/c/Program Files/dotnet/:/mnt/c/Program Files (x86)/NVIDIA Corporation/PhysX/Common:/mnt/c/Program Files/Rancher Desktop/resources/resources/win32/bin/:/mnt/c/Program Files/Rancher Desktop/resources/resources/win32/docker-cli-plugins/:/mnt/c/Program Files/Rancher Desktop/resources/resources/linux/bin/:/mnt/c/Program Files/Rancher Desktop/resources/resources/linux/docker-cli-plugins/:/mnt/c/Program Files/Amazon/AWSCLIV2/:/mnt/c/Users/myuser/AppData/Local/Programs/Python/Python312:/mnt/c/Users/myuser/AppData/Local/Programs/Python/Python312/Scripts:/mnt/c/Program Files/Amazon/SessionManagerPlugin/bin/:/mnt/c/Users/myuser/AppData/Local/Programs/Python/Launcher/:/mnt/c/Users/myuser/AppData/Local/Microsoft/WindowsApps:/mnt/c/Users/myuser/AppData/Local/Programs/Git/cmd:/mnt/c/Users/myuser/AppData/Local/JetBrains/Toolbox/scripts:/mnt/c/Program Files/JetBrains/IntelliJ IDEA 2024.2.3/bin:/mnt/c/Users/myuser/AppData/Local/Programs/Microsoft VS Code/bin:/mnt/c/Users/myuser/AppData/Local/Programs/Python/Python312:/snap/bin:/usr/local/bin"
      **+ PYTHON = "/usr/bin/python3"**
    }

This path and python location match what I have locally..

But when I use below github actions workflow:

  - name: Init
    uses: gruntwork-io/terragrunt-action@v2
    with:
      tf_version: ${{ env.tf_version }}
      tg_command: 'init'
      tg_comment: true
      tg_dir: accounts/${{ github.event.inputs.aws_account_name }}/${{ github.event.inputs.aws_region }}/service
      tg_version: ${{ env.tg_version }}
    
  - name: Plan
    uses: gruntwork-io/terragrunt-action@v2
    with:
      tf_version: ${{env.tf_version}}
      tg_command: 'plan'
      tg_comment: true
      tg_dir: accounts/${{ github.event.inputs.aws_account_name }}/${{ github.event.inputs.aws_region }}/service
      tg_version: ${{env.tg_version}}

I get:

  + debug_info = {
      + PATH   = "/github/home/.local/share/mise/installs/terraform/1.7.5/bin:/github/home/.local/share/mise/installs/terragrunt/0.55.16/bin:~/.local/share/mise/shims:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
      **+ PYTHON = ""**
    }

That is python is not available. I have tried installing python3 in workflow and checked the path, and that path does not match to path I get from terragrunt plan.

I am not sure why this doesn't work, anybody any clue?

TF version: 1.7.5 TG version: 0.55.16