Review a buildspec.yml

At NovaTech, your team uses a buildspec.yml to define how CodeBuild compiles and tests a Python Lambda application. Use the buildspec explorer to examine the build configuration.

The explorer shows a complete buildspec.yml with all four phases (install, prebuild, build, postbuild) and the artifacts section. You can toggle phases on and off to see simulated build logs and understand what each phase contributes.

Pay attention to the artifacts section — this defines what gets passed to the Deploy stage. Getting the file paths wrong is the most common cause of deployments that fail after a "successful" build.

Question: A CodeBuild project succeeds (all four phases pass), but CodeDeploy fails immediately with "The specified key does not exist." What is the most likely cause?