danger: Danger fails on CI when running on PR from a fork in GH Actions / Buddy Build

Using:

      - uses: actions/checkout@v2

Will only checkout the single commit to be tested-you need something with more depth, so you can either use actions/checkout@v1 or specify the fetch-depth as in:

      - uses: actions/checkout@v2
        with:
          fetch-depth: 0

This solved my issues with Github Actions 😄

so I tried to work around this today, and while I didn’t get a solution, I think what i found may be enlightening.

I added a step to checkout the fork remote:

      - run: |
          set -x
          echo $GITHUB_BASE_REF
          echo $GITHUB_HEAD_REF
          echo $EVENT
          echo $PR_REPO
          echo $BASE_REPO
          # should be PR_REPO_URL, but that doesn't exist
          # for some reason...
          git remote add pr https://github.com/$PR_REPO
          git fetch pr
          git remote -v
          git checkout $PR_HEAD
          git show
        if: github.event.pull_request.head.repo.full_name != github.repository
        env:
          EVENT: ${{ github.event_name }}
          PR_REPO: ${{ github.event.pull_request.head.repo.full_name }}
          PR_REPO_URL: ${{ github.event.pull_request.head.repo.clone_url }}
          BASE_REPO: ${{ github.repository }}
          PR_HEAD: ${{ github.event.pull_request.head.ref }}

When I did that, however, Danger, I think, ended up comparing the branch to itself, and saw no delta, and thus was very happy.

So then I tried to pass in --base:

      - run: |
          danger --verbose --fail-on-errors=true --base=$BASE
        env:
          BASE: ${{ github.event.pull_request.base.ref }}
          DANGER_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}

But then it complains it can’t find main anywhere in the repo (Commit main doesn't exist). That can’t be right!

I then tried dropping the checkout, but that didn’t work either. I even tried modifying my git-fix step to be:

          git checkout -b main origin/main
          git checkout $PR_HEAD

to make sure the right main and the right head would be there. This gets the right things in the right places:

+ git remote -v
origin	https://github.com/chef/chef (fetch)
origin	https://github.com/chef/chef (push)
pr	https://github.com/jaymzh/chef (fetch)
pr	https://github.com/jaymzh/chef (push)
+ git checkout -b main origin/main
Previous HEAD position was 63aab93aff Merge cb81921547c7a0b0bdac3ebdf66f7726e5210015 into 3e18296d7e4f1a175f43f41d08173c708634cd8c
Switched to a new branch 'main'
branch 'main' set up to track 'origin/main'.
+ git checkout dangerfix
Switched to a new branch 'dangerfix'
branch 'dangerfix' set up to track 'pr/dangerfix'.

But, this, once again, caused danger to simply see nothing.

I tried at this point modifying danger call to be this, though I think this is what it does by default:

      - run: |
          danger --verbose --fail-on-errors=true --base=$BASE --head=$PR_HEAD
        env:
          BASE: ${{ github.event.pull_request.base.ref }}
          PR_HEAD: ${{ github.event.pull_request.head.ref }}
          DANGER_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}

But it sees nothing.

So then I decided to add message(git.diff) to see what diff it thinks it’s seeing.

Low and behold, it’s my diff. It crashes on unless source.valid_encoding? (https://github.com/chef/chef/actions/runs/7148990967/job/19470679407?pr=14134), but in the stacktrace I can see the diff.

So at this point, given I’ve made sure that both the base ref and the head ref are both there, I think it seems reasonable to believe there’s something that Danger isn’t quite catching here.

@Xorima

@SgtPooki can you post the full action workflow you are using as I’m struggling to recreate it

it’s in ipfs/awesome-ipfs repo (https://github.com/ipfs/awesome-ipfs/blob/master/.github/workflows/pull_requests.yml). Also, there was some feedback on the PR or issue I created in that repo from galargh that you may find valuable regarding what setting pull_request_target actually does.

idk if this will fix everyone’s problems, but changing github workflow trigger from pull_request to pull_request_target resolved the issue for me. see https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target