Self Hosted Runner not running completing actions

Im finding my way with GitHub actions. I have played with some examples using the Github hosted runners and all of the test workflows Ive tried complete ok. However when I go to try running them on a self hosted runner they do not complete. 

For example I run this 

on:
  push:
    branches: [master]
  pull_request:
    branches: [master]

# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
  # This workflow contains a single job called "build"
  build:
    # The type of runner that the job will run on
    runs-on: macos-latest

    # Steps represent a sequence of tasks that will be executed as part of the job
    steps:
    - uses: actions/checkout@v2
    - name: Set up Python
      uses: actions/setup-python@v1
      with:
        python-version: '3.8'
    - name: Install dependencies
      run: python -m pip install --upgrade pip setuptools wheel

And it works fine 

if I change my runner to my self hosted

[self-hosted, macOS, x64]

And then run the workflow again I get the following error, listing no available versions:

Check failure on line 1 in .github

@github-actions
github-actions
/ build

.github#L1
Version 3.8 with arch x64 not found
Available versions:

The only thing I can get to work on a self hosted runner is

uses: actions/checkout@v2

As soon as I add any steps that install anything it fails. The runner is running under admin and I have also tried this on a Windows runner. That fails also 

Ive also tried this on the self hosted runner.

steps:
- uses: actions/checkout@v2
- uses: actions/setup-python@v2
  with:
    python-version: '3.x' # Version range or exact version of a Python version to use, using SemVer's version range syntax
    architecture: 'x64

This fails with 

The process '/bin/bash' failed with exit code 1. 

 Again it works fine on the github hosted runners

I must be missing something! My runners are setup to use external actions. 

@mradev 

This will not help you but I believe you are running into the same problem I faced. You may have a look to the answer I get here

My issue is still not fully solved as I need to launch the Runner with elevated rights.

Hi @mradev , 

There is an open issue for using actions/setup-python@v2 in self-hosted runner: https://github.com/actions/setup-python/issues/89

Please follow on this issue to get updates from the author of setup-python action. 

Thanks ill investigate. One thing to point out though I have found that I have to run the runner script as root for anything to install on a self hosted runner. Root user is blocked in the script  so had to comment these lines for the script to run as sudo. Some clarity on why the guidance is not to run as root but it not working in many cases if not would be useful. 

@galleon  Thanks. There seems to be a further issue but root perms seems to be necessary on self hosted runners

The Readme.md file of setup-python action has been updated. There are a few extra things you need to make sure are set up so that new versions of Python can be downloaded and configured on your self-hosted runner. Please follow the document https://github.com/actions/setup-python#using-setup-python-with-a-self-hosted-runner

Let me know whether this works in your side.