Renovate GitHub-native automerge debug message when merge method is not allowed

[HonkingGoose]

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No response

If you're self-hosting Renovate, tell us what version of Renovate you run.

28.8.3

Describe the bug

Intro

I'm trying out the new automerge on my honkinggoose/gitgosling repo, with Renovate version 28.8.3.

Steps to reproduce:

1. The repository had no pending PRs.
2. I requested a lockfile update via the Dashboard.
3. I wondered what the behavior is now, so I checked the logs from this run (pasted below in log section of bug report).
4. I was expecting Renovate to automerge the lockfile right away, as it's the only PR and it's fully up to date with main right when its created.
5. Instead I got a debug message: "message": "Merge method merge commits are not allowed on this repository"

Repo settings

On my repository I only allow squash merges:

I also have a branch protection rule stating that any PR branch must be up-to-date with main before it can be merged.

Further context

Link to PR that had the debug logs: HonkingGoose/git-gosling#313
Note that Renovate did manage to automerge the PR in the end, but I think it used the Renovate fallback to do that.

If GitHub-native automerge requires that the normal merge is available we should document that, because we don't mention this right now.

@rarkins thought:

Seems we need a way to detect merge type

Relevant debug logs

Relevant logs for initial run

DEBUG: getBranchStatus(renovate/lock-file-maintenance)(branch="renovate/lock-file-maintenance")
DEBUG: branch status check result(branch="renovate/lock-file-maintenance")
{
  "state": "pending",
  "statuses": []
}
DEBUG: No check runs found(branch="renovate/lock-file-maintenance")
{
  "result": {
    "total_count": 0,
    "check_runs": []
  }
}
DEBUG: Branch status yellow(branch="renovate/lock-file-maintenance")
DEBUG: Creating PR(branch="renovate/lock-file-maintenance")
{
  "prTitle": "chore(deps): lock file maintenance"
}
DEBUG: Creating PR(branch="renovate/lock-file-maintenance")
{
  "title": "chore(deps): lock file maintenance",
  "head": "HonkingGoose:renovate/lock-file-maintenance",
  "base": "main",
  "draft": false
}
DEBUG: PR created(branch="renovate/lock-file-maintenance")
{
  "pr": 313,
  "draft": false
}
DEBUG: Adding labels '' to #313(branch="renovate/lock-file-maintenance")
DEBUG: GitHub automerge unknown error(branch="renovate/lock-file-maintenance")
{
  "prNumber": 313,
  "errors": [
    {
      "type": "UNPROCESSABLE",
      "path": [
        "enablePullRequestAutoMerge"
      ],
      "locations": [
        {
          "line": 5,
          "column": 3
        }
      ],
      "message": "Merge method merge commits are not allowed on this repository"
    }
  ]
}
INFO: PR created(branch="renovate/lock-file-maintenance")
{
  "pr": 313,
  "prTitle": "chore(deps): lock file maintenance"
}
DEBUG: Skipping assignees and reviewers as automerge=true(branch="renovate/lock-file-maintenance")
DEBUG: Created Pull Request #313(branch="renovate/lock-file-maintenance")
DEBUG: PR is configured for automerge(branch="renovate/lock-file-maintenance")
DEBUG: PR is not ready for merge(branch="renovate/lock-file-maintenance")
DEBUG: getBranchPr(renovate/lock-file-maintenance)
DEBUG: findPr(renovate/lock-file-maintenance, undefined, open)
DEBUG: Found PR #313
DEBUG: PR not found in open or closed PRs list - trying to fetch it directly
{
  "prNo": 313
}
DEBUG: Ensuring Dependency Dashboard
DEBUG: ensureIssue(Dependency Dashboard)
DEBUG: Patching issue
DEBUG: Issue updated
DEBUG: Removing any stale branches
DEBUG: config.repoIsOnboarded=true
DEBUG: Branch lists
{
  "branchList": [
    "renovate/lock-file-maintenance",
    "renovate/npm-8.x"
  ],
  "renovateBranches": [
    "renovate/lock-file-maintenance"
  ]
}
DEBUG: remainingBranches=
DEBUG: No branches to clean up
DEBUG: Repository timing splits (milliseconds)
{
  "splits": {
    "init": 2411,
    "extract": 2967,
    "lookup": 2479,
    "update": 130426
  },
  "total": 139426
}

Relevant logs for run that automerged the lockfile PR

DEBUG: Branch status green(branch="renovate/lock-file-maintenance")
DEBUG: Processing existing PR(branch="renovate/lock-file-maintenance")
DEBUG: Pull Request #313 does not need updating(branch="renovate/lock-file-maintenance")
DEBUG: PR is configured for automerge(branch="renovate/lock-file-maintenance")
DEBUG: resolveBranchStatus(branchName=renovate/lock-file-maintenance, ignoreTests=false)(branch="renovate/lock-file-maintenance")
DEBUG: getBranchStatus(renovate/lock-file-maintenance)(branch="renovate/lock-file-maintenance")
DEBUG: branch status check result(branch="renovate/lock-file-maintenance")
{
  "state": "success",
  "statuses": [
    {
      "url": "https://api.github.com/repos/HonkingGoose/git-gosling/statuses/2b9cedd52417d823105802e402932d23f354d9fb",
      "avatar_url": "https://avatars.githubusercontent.com/in/8329?v=4",
      "id": 14944469753,
      "node_id": "SC_kwDOEbfyB88AAAADesKC-Q",
      "state": "success",
      "description": "Deployment has completed",
      "target_url": "https://vercel.com/honkinggoose/git-gosling/EBFgt4sMCXh7utZs9nu4zRzTQLYM",
      "context": "Vercel",
      "created_at": "2021-10-23T07:14:57Z",
      "updated_at": "2021-10-23T07:14:57Z"
    }
  ]
}
DEBUG: check runs result(branch="renovate/lock-file-maintenance")
{
  "checkRuns": [
    {
      "name": "build (14.x)",
      "status": "completed",
      "conclusion": "success"
    },
    {
      "name": "lint (14.x)",
      "status": "completed",
      "conclusion": "success"
    }
  ]
}
DEBUG: Branch status green(branch="renovate/lock-file-maintenance")
DEBUG: Automerging #313 with strategy auto(branch="renovate/lock-file-maintenance")
DEBUG: mergePr(313, renovate/lock-file-maintenance)(branch="renovate/lock-file-maintenance")
DEBUG: mergePr(branch="renovate/lock-file-maintenance")
{
  "options": {
    "body": {
      "merge_method": "squash"
    }
  },
  "url": "repos/HonkingGoose/git-gosling/pulls/313/merge"
}
DEBUG: PR merged(branch="renovate/lock-file-maintenance")
{
  "automergeResult": {
    "sha": "ec34406e5fa1722a1a1efa8a9add78593a5f9bc6",
    "merged": true,
    "message": "Pull Request successfully merged"
  },
  "pr": 313
}
INFO: PR automerged(branch="renovate/lock-file-maintenance")
{
  "pr": 313,
  "prTitle": "chore(deps): lock file maintenance"
}
DEBUG: No remote branch to delete(branch="renovate/lock-file-maintenance")
{
  "branchName": "renovate/lock-file-maintenance"
}
DEBUG: No local branch to delete(branch="renovate/lock-file-maintenance")
{
  "branchName": "renovate/lock-file-maintenance"
}
INFO: Renovating repository again after automerge result

Have you created a minimal reproduction repository?

No reproduction, but I have linked to a public repo where it occurs

[viceice]

I don't think it's merge type dependent, as we use it via UI with squash merge.

[ylemkimon]

The merge method should be specified in the enablePullRequestAutoMerge mutation:
https://docs.github.com/en/graphql/reference/input-objects#enablepullrequestautomergeinput

mergeMethod: The merge method to use. If omitted, defaults to 'MERGE'.

[rarkins]

@zharinov let's default it to merge squash and add try/catch/try/etc like we do with regular automerge

[ylemkimon]

The merge method exists in the Renovate config, doesn't it?

renovate/lib/platform/github/index.ts

Lines 239 to 244 in 7a54591

	if (repo.rebaseMergeAllowed) {
	config.mergeMethod = 'rebase';
	} else if (repo.squashMergeAllowed) {
	config.mergeMethod = 'squash';
	} else if (repo.mergeCommitAllowed) {
	config.mergeMethod = 'merge';

[ylemkimon]

This would be fixed by #12393 and #12398.