no such identity on self-hosted Linux Github runner

[Robert-DEMCON]

I have setup a self hosted runner on Linux for my Github workflow and I am using ssh-agent to provide access to private repos dependencies.

On git clone ... I get an error:

Cloning into 'repo 2'...
no such identity: /home/github/.ssh/key-fffb0082e1157c90572...: No such file or directory

But in the webfactory/ssh-agent step before the clone I see the following output:

Adding private key(s) to agent
Identity added: (stdin) ([email protected]:repo1.git)
Identity added: (stdin) ([email protected]:repo2.git)
Key(s) added:
3072 SHA256:hAs1tUrOBaHbagBJZ... [email protected]:repo1.git (RSA)
3072 SHA256:Q77jCBXY8ISwrfJBp... [email protected]:repo2.git (RSA)
Configuring deployment key(s)
Added deploy-key mapping: Use identity '/home/github/.ssh/key-1f819af0a2d0117f7a1c4...' for GitHub repository repo1
Added deploy-key mapping: Use identity '/home/github/.ssh/key-7c10775661e565cd952033acf519154...' for GitHub repository repo2

Both keys have a different identity than mentioned on the error. Is this maybe a caching problem?

---

Relevant workflow job:

jobs:
  tests:
    runs-on: self-hosted
    steps:
      - name: Place SSH private key to grant access to other repos
        uses: webfactory/[email protected]
        with:
          ssh-private-key: |
            ${{ secrets.PRIVATE_KEY_FOR_REPO1 }}
            ${{ secrets.PRIVATE_KEY_FOR_REPO2 }}
      - run: |
          rm -rf tmp && mkdir -p tmp && cd tmp
          git clone [email protected]:repo1.git
          git clone [email protected]:repo2.git

---

I already use the same runner another repository's CI with ssh-agent with success.

[Robert-DEMCON]

Doing a grep on the faulty key (fffb0082e1157c90572...) I saw an entry in /home/github/.gitconfig, in the system user that does the runner. It looks like data persists from the other workflow that conflicts with this one.

After removing the file the job succeeds.

Can I use a local and temporary folder specific to each workflow instead of the system user home directory?

[Robert-DEMCON]

I ended up working around this by adding a step to change the home directory first for the rest of the actions:

      - run: echo "HOME=$RUNNER_TEMP/github" >> "$GITHUB_ENV"

However, this does not change the location of the key files, they will still end up in /home/github/.ssh.
But the .gitconfig file will now be placed under the job temp directory. And this seems to work.