Bazel BEP Failure Analyzer Buildkite Plugin

A fast Buildkite plugin that analyzes Bazel Event Protocol (BEP) protobuf files and creates focused annotations for build failures. Prefers native protobuf parsing when available for accuracy and performance, with a safe string-based fallback.

Features

• ⚡ Fast BEP processing — scales to very large builds
• 🎯 Failure-focused — concise, actionable failure details
• 🔗 GitHub linking — direct links to failing files/lines
• 🔍 Auto-detection — finds BEP files in common locations
• 🧰 Minimal deps — requires Bash and Python 3; protobuf is optional
• 🚨 Clear annotations — designed for Buildkite’s annotation UI
• 🛠️ Bazel-native — understands Bazel BEP failure types
• 🔁 Robust — retries annotation creation on transient errors

Prerequisites

• Bash
• Python 3
• Bazel (to generate BEP files)
• Optional: Python protobuf package (recommended for best parsing)

Without protobuf, the analyzer falls back to string-based parsing.

Plugin Options

bep_file (optional)

Path to the Bazel Event Protocol protobuf file to parse. If not provided, the plugin looks for common filenames: bazel-events.pb, bazel-bep.pb, bep.pb, events.pb.

skip_if_no_bep (optional, boolean)

If true, the plugin exits successfully when no BEP file is found. Default: false

Processing Limits and Behavior

To ensure reliability and prevent memory issues, the analyzer enforces limits (configurable):

• File size: 100MB max BEP file size (--max-file-size in MB)
• Failure count: 50 failures max (--max-failures)
• Annotation size: 1MB (Buildkite platform limit)

When limits are exceeded, warnings are logged and results are truncated safely. Defaults are defined in bin/config.py.

Examples

Basic usage with explicit BEP file

steps:
  - label: "🔨 Build with Bazel"
    command: |
      bazel build //... --build_event_binary_file=bazel-events.pb
    plugins:
      - bazel-annotate#v1.1.1:
          bep_file: bazel-events.pb

Skip annotations if no BEP file found

steps:
  - label: "🔨 Build with Bazel"
    command: |
      # Command might not produce a BEP file
      bazel build //...
    plugins:
      - bazel-annotate#v1.1.1:
          skip_if_no_bep: true

Running tests with annotations

steps:
  - label: "🧪 Run Bazel tests"
    command: |
      bazel test //... --build_event_binary_file=bazel-test-events.pb
    plugins:
      - bazel-annotate#v1.1.1:
          bep_file: bazel-test-events.pb

Multiple Bazel jobs in a pipeline with separate annotations

steps:
  - label: "🔨 Build with Bazel"
    command: |
      bazel build //... --build_event_binary_file=bazel-build-events.pb
    plugins:
      - bazel-annotate#v1.1.1:
          bep_file: bazel-build-events.pb

  - label: "🧪 Test with Bazel"
    command: |
      bazel test //... --build_event_binary_file=bazel-test-events.pb
    plugins:
      - bazel-annotate#v1.1.1:
          bep_file: bazel-test-events.pb

  - label: "📦 Package with Bazel"
    command: |
      bazel run //:package --build_event_binary_file=bazel-package-events.pb
    plugins:
      - bazel-annotate#v1.1.1:
          bep_file: bazel-package-events.pb

Development

• Run shell tests in Docker:

docker compose run --rm tests bats tests

• Run Python unit tests locally:

python3 -m unittest -v tests/test_analyzer.py

• Linting and Shellcheck are covered in the Buildkite pipeline for the plugin (see .buildkite/pipeline.yml).

Compatibility

Elastic Stack	Agent Stack K8s	Hosted (Mac)	Hosted (Linux)	Notes
📝	📝	✅	📝	Agents on Linux/K8s need Bazel available

• ✅ Fully supported
• 📝 Agents running on Linux or Kubernetes must provide Bazel

👩‍💻 Contributing

1. Fork the repository
2. Create a feature branch
3. Add your changes, including tests
4. Submit a pull request

📜 License

The package is available as open source under the terms of the MIT License.