How to avoid setting ACTIONS_ALLOW_UNSECURE_COMMANDS for setup-python? - github-actions

Question

Github Actions' actions/setup-python step doesn't succeed due to the use of ::set-env: and ::add-path:, that are blocked because considered as insecure (https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands).
Succeed by setting ACTIONS_ALLOW_UNSECURE_COMMANDS=true environment variable for this step.
How to avoid allowing unsecure commands to successfully run a Python build?
Self-hosted runner in a custom-built docker with Ubuntu 20.04 base image. Linked to an GHE server v2.22.4.
Tried with both Python 3.9.0 and 3.9.1
Workflow file:
name: CD testing
on:
push:
branches: [ master ]
pull_request:
branches: [ master ]
jobs:
runs-on: [ Linux ]
- uses: actions/checkout#v2
- name: setup python
uses: actions/setup-python#v2
with:
python-version: 3.9.0
- name: execute py script
run: |
python -V
##[debug]Found tool in cache Python 3.9.1 x64
::set-env name=pythonLocation::/opt/hostedtoolcache/Python/3.9.1/x64
##[error]Unable to process command '::set-env name=pythonLocation::/opt/hostedtoolcache/Python/3.9.1/x64' successfully.
##[error]The `set-env` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug]System.Exception: The `set-env` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug] at GitHub.Runner.Worker.SetEnvCommandExtension.ProcessCommand(IExecutionContext context, String line, ActionCommand command, ContainerInfo container)
##[debug] at GitHub.Runner.Worker.ActionCommandManager.TryProcessCommand(IExecutionContext context, String input, ContainerInfo container)
::add-path::/opt/hostedtoolcache/Python/3.9.1/x64
##[error]Unable to process command '::add-path::/opt/hostedtoolcache/Python/3.9.1/x64' successfully.
##[error]The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug]System.Exception: The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug] at GitHub.Runner.Worker.AddPathCommandExtension.ProcessCommand(IExecutionContext context, String line, ActionCommand command, ContainerInfo container)
##[debug] at GitHub.Runner.Worker.ActionCommandManager.TryProcessCommand(IExecutionContext context, String input, ContainerInfo container)
::add-path::/opt/hostedtoolcache/Python/3.9.1/x64/bin
##[error]Unable to process command '::add-path::/opt/hostedtoolcache/Python/3.9.1/x64/bin' successfully.
##[error]The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug]System.Exception: The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
##[debug] at GitHub.Runner.Worker.AddPathCommandExtension.ProcessCommand(IExecutionContext context, String line, ActionCommand command, ContainerInfo container)
##[debug] at GitHub.Runner.Worker.ActionCommandManager.TryProcessCommand(IExecutionContext context, String input, ContainerInfo container)
::set-output name=python-version::3.9.1
##[debug]='3.9.1'
Successfully setup CPython (3.9.1)

Answer 1

Update actions/setup-python which uses set-env in previous versions from
- uses: actions/setup-python#v2
to the latest version
- uses: actions/setup-python#v2.2.1
There's a bug - v2 does not use the latest version.