DOP-C02 SDLC Automation Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The CodeBuild project is configured with a VPC that restricts access to external dependency repositories.

  Why it's wrong here

  A CodeBuild project with a VPC configured to restrict access to external dependency repositories would typically cause consistent, build-wide failures — every dependency download or package install would hit network errors, not just specific tests. Such a misconfiguration would produce errors like 'unable to resolve dependency' or timeout errors during the install phase, which are deterministic. In contrast, the problem statement describes intermittent test failures while other phases succeed, so a network egress restriction cannot explain tests passing locally but failing in CodeBuild. VPC issues affect all builds equally, not a subset of test cases.

• ✗

  The CodePipeline has a timeout setting that causes the build to be terminated before tests complete.

  Why it's wrong here

  A CodePipeline timeout (or CodeBuild build timeout) terminates the entire build process after a fixed duration, regardless of whether tests are passing or failing. Timeout misconfigurations cause consistent 'TIMED OUT' errors across every run, not occasional test assertion failures. Moreover, the default build timeout in CodeBuild is 60 minutes, which is generally sufficient for a standard test suite; if a timeout were the issue, you would not see flaky, intermittent test results that differ between runs. Therefore, a timeout setting is not a plausible cause for tests that fail non-deterministically in CodeBuild.

• ✗

  The CodePipeline is configured with a branch filter that only triggers on the 'main' branch.

  Why it's wrong here

  A branch filter in the CodePipeline source action would prevent the pipeline from executing at all for 'develop' branch commits, leaving developers with no build or test results. The symptom of intermittent test failures implies builds are being triggered and running to completion — meaning the pipeline is actively executing. A branch filter is a binary gate: either the pipeline triggers or it doesn't — it cannot selectively cause individual tests to fail. Thus, this option explains a lack of pipeline runs, not flaky test outcomes.

• ✓

  The CodeBuild project has different environment variables or dependency versions compared to the local environment.

  Why this is correct

  CodeBuild executes in a managed build environment that uses a specified image (e.g., Amazon Linux with a particular JDK, Node.js, or Python version) and its own set of environment variables and pre-installed tool versions, which may differ from the developer's local machine. Dependency resolution without strict lockfiles can pull different minor or patch versions of libraries in CodeBuild than those present locally, leading to behavioral changes that break tests intermittently. Similarly, environment variables such as API endpoints, feature flags, or locale settings can alter application logic at runtime. This environmental divergence is the classic 'works on my machine' problem and directly explains why tests pass locally but intermittently fail in CodeBuild.

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