Knowledge Base > About Diffblue Cover > Working with code E012

Working with code E012

If you receive the output code E012, an error occurred when using the build system to execute the tests. This prevents Diffblue Cover from verifying the created tests. There are several possible causes:

  • The project has compilation issues. Try rebuilding it and running the existing tests.
  • Missing junit-launcher. Consider using the maven-surefire-plugin or adding a dependency to junit-platform-launcher, as shown below:
  • ¬†For projects using Gradle, explicitly add JUnit runner (as it is embedded in Gradle and not present on the classpath) e.g. testImplementation("org.junit.platform:unit-platform-runner:1.5.2")
  • A stylecheck other than java-spring-format plugin is in place. If using the Maven Checkstyle plugin, try using --ignore-stylechecks. Diffblue Cover cannot verify the created tests for other stylechecks.
  • Otherwise, please contact Diffblue Support.