name: step-analysis description: Analyzes why Buildkite pipeline steps were skipped, didn't run, or behaved unexpectedly. Use when a user asks why a step didn't execute, was skipped, or wants to understand step dependencies.

Step Analysis

You are helping a user understand why a pipeline step didn't run as expected, was skipped, or behaved unexpectedly.

Approach

1. Get Build Information

   • Use buildkite_get_build to fetch the build with all job details
   • Look at each job's state field to understand what happened
   • Check for skipped, blocked, waiting, waiting_failed states

2. Analyze Step States

   State	Meaning
   scheduled	Waiting to be assigned to an agent
   assigned	Assigned to agent, waiting to start
   accepted	Agent accepted, starting soon
   running	Currently executing
   passed	Completed successfully
   failed	Command returned non-zero exit
   blocked	Waiting for manual unblock
   canceled	User or system cancelled
   canceling	In process of cancelling
   skipped	Skipped due to condition
   not_run	Dependency failed, step not run
   waiting	Waiting for dependency
   waiting_failed	Waiting but will not run
   timed_out	Exceeded timeout

3. Check Pipeline Configuration

   • If the user has a pipeline.yml, read it to understand the intended flow
   • Look for these step-control fields:
     • if: Conditional expression that must evaluate to true
     • depends_on: Steps that must complete first
     • allow_dependency_failure: Whether to run if dependency failed
     • branches: Branch filter patterns
     • skip: Explicit skip condition

4. Investigate Specific Scenarios

Step Skipped

• Check the if condition - what variables were evaluated?
• Look at branch filters - does this branch match?
• Check if skip: true or a skip message was set
• Review build metadata that might affect conditions

Step Didn't Run (not_run state)

• Identify which dependency failed using depends_on
• Check if allow_dependency_failure: true was set
• Look at the dependency chain - find the root failure

Step Stuck in Waiting

• Check what it's waiting for: dependency, agent, or block
• If waiting for agents: check queue and agent tags
• If blocked: check who can unblock and current state

Step Timed Out

• Check timeout_in_minutes setting
• Look at logs to see what was happening when timeout hit
• Consider if the step is legitimately slow or stuck

Understanding Conditionals

Buildkite if conditions can reference:

• build.branch - Branch name
• build.tag - Tag name (if tag build)
• build.message - Commit message
• build.source - What triggered the build (webhook, ui, api, schedule)
• build.env.* - Environment variables
• build.meta_data.* - Build metadata
• build.pull_request.* - PR information

Example conditions:

# Only on main
if: build.branch == "main"

# Skip for PRs from forks
if: build.pull_request.repository.fork != true

# Only when specific files changed
if: build.env.BUILDKITE_PLUGINS =~ /docker/

Response Format

1. What Happened: Clear explanation of the step's state
2. Why: The specific condition or dependency that caused this
3. Evidence: Point to the exact configuration or build data
4. Resolution: How to change behavior if desired

Important Notes

• Always fetch the actual build data - don't guess about step states
• If the pipeline YAML is available, cross-reference with actual execution
• Consider that dynamic pipelines may modify steps at runtime
• Group steps can affect how dependencies are interpreted