prConcurrentLimit set inside a packageRule narrows the threshold but doesn't scope the counter

[Amine-Mike]

How are you running Renovate?

Self-hosted Renovate CLI

Which platform you running Renovate on?

GitLab (.com or self-hosted)

Which version of Renovate are you using?

43.253.2

Please tell us more about your question or problem

We tried to give different dependency groups independent concurrent-PR quotas
(e.g. "at most 2 open npm branches AND at most 2 open pep621/python branches,
independent of each other") using packageRules:

  {
    "prConcurrentLimit": 4,
    "packageRules": [
      { "matchManagers": ["npm"], "prConcurrentLimit": 2 },
      { "matchManagers": ["pep621"], "prConcurrentLimit": 2 }
    ]
  }

We expected this to behave like two independent buckets (up to 2 npm + up to 2
pep621 = up to 4 concurrent total, matching the global prConcurrentLimit).

Instead, once any 2 branches exist in the repo — regardless of manager — every
other branch whose matching rule also resolves to a limit of 2 gets permanently
blocked, even if none of the existing branches belong to that manager. In our
case, two npm branches were created first, and every subsequent pep621 (python)
dependency has been blocked from ever getting a branch, indefinitely.

Logs (if relevant)

Logs

  DEBUG: syncBranchState() (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: syncBranchState(): Branch cache not found, creating minimal branchState (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: getBranchPr(renovate/aiokafka-0.x) (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: findPr(renovate/aiokafka-0.x, undefined, open) (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: branchExists=false (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: dependencyDashboardCheck=undefined (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: recreateClosed is true. No need to check for closed PR. (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: Open PR Count: 2, Existing Branch Count: 2, Hourly PR Count: 0, Hourly Commit Count: 0 (repository=org/repo, baseBranch=main,
  branch=renovate/aiokafka-0.x)
  DEBUG: prHourlyLimit of the upgrades present in this branch (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
         "limits": [{"depName": "aiokafka", "prHourlyLimit": 4}]
  DEBUG: Calculated lowest prHourlyLimit among the upgrades present in this branch is 4. (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
  DEBUG: branchConcurrentLimit of the upgrades present in this branch (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
         "limits": [{"depName": "aiokafka", "branchConcurrentLimit": null}]
  DEBUG: Calculated lowest branchConcurrentLimit among the upgrades present in this branch is 2. (repository=org/repo, baseBranch=main,
  branch=renovate/aiokafka-0.x)
  DEBUG: Branches limit reached (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)
         "limitKey": "branchConcurrentLimit",
         "currentCount": 2
  DEBUG: Reached branch limit - skipping branch creation (repository=org/repo, baseBranch=main, branch=renovate/aiokafka-0.x)