Troubleshooting CircleCI Build Failures with No Error Output

Overview

Experiencing a build failure in CircleCI without any error output can be puzzling. This article explores common causes for such failures and provides guidance on how to resolve them. It also addresses a specific scenario where the use of an incompatible Docker image led to a build reporting failure despite individual tasks succeeding.

Prerequisites

• Access to your CircleCI account.
• Familiarity with CircleCI configuration files (.circleci/config.yml).
• Understanding of Docker and containerization.

Instructions

When encountering a build failure with no error output, consider the following steps to diagnose and fix the issue:

1. Verify Language and Package Versions: Ensure that the language and package versions match between your local environment and CircleCI.
2. Check Timezone Configurations: Confirm that your testing frameworks and build configurations are timezone-aware.
3. Inspect File Ordering: Some tests may fail if they depend on a specific file order. CircleCI's filesystems are unordered, so ensure your tests do not rely on file ordering.
4. Monitor Memory Usage: Look out for "Out of Memory" errors which can terminate processes unexpectedly.
5. Adjust for Startup Times: Services like databases may take longer to start on CircleCI. Implement explicit wait times in your config.
6. Validate External Services: If your build depends on third-party services, check their availability and operational status.
7. Review CircleCI Configuration: Examine your .circleci/config.yml for syntax errors or misconfigurations.
8. Isolate Failing Steps: Try to pinpoint the exact step where the build fails to narrow down the cause.
9. Update Dependencies: Ensure all external dependencies and tools are up-to-date and compatible with your build.

Solution

In a specific case, the issue was resolved by switching to a different Docker image that was compatible with the build requirements. The original image was a binary-only Docker image, which lacked an underlying operating system, making it unsuitable for the build process. Using an Alpine-based image instead led to a successful build.

If you encounter a similar issue, try the following:

1. Identify the Docker image used in your build.
2. Replace the binary-only image with an Alpine-based image or another image that includes the necessary environment for your build.
3. Update your .circleci/config.yml to reference the new image.
4. Rerun the build to check if the issue is resolved.

Additional Resources

• CircleCI Configuration Reference
• CircleCI Docker Image Reference
• Debugging with SSH on CircleCI

Remember, when troubleshooting builds, it's essential to consider all aspects of your CI/CD pipeline, from the configuration file to the Docker images and external dependencies.