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JobDependencyCycle

Cycle in job dependencies (needs).

Defined by JobDependenciesRule which supports workflows in the "Default" ruleset along with MissingNeedsJob.

Description

Having a cycle in the job dependency graph is an error. There must be a starting point in the workflow to start the workflow run.

GitHub may give an error similar to this:

The workflow is not valid. .github/workflows/???.yml (Line: ?, Col: ?): The workflow must contain at least one job with no dependencies.

Compliant examples

Compliant example #1

Jobs don't have dependencies.

example.yml 

name: "My Workflow"
on: push
jobs:
  example:
    name: "My Job"
    uses: reusable/workflow.yml

Compliant example #2

There's a job to start with (example1).

example.yml 

name: "My Workflow"
on: push
jobs:
  example1:
    name: "My Job"
    uses: reusable/workflow.yml
  example2:
    name: "My Job"
    needs: example1
    uses: reusable/workflow.yml

Non-compliant example

Circular dependency between jobs.

example.yml 

name: "My Workflow"
on: push
jobs:
  example1:
    name: "My Job 1 -> 2"
    needs: example2
    uses: reusable/workflow.yml
  example2:
    name: "My Job 2 -> 1"
    needs: example1
    uses: reusable/workflow.yml

  • Line 4: Job[example1] forms a dependency cycle: [example1, example2].