> For the complete documentation index, see [llms.txt](https://cover-docs.diffblue.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cover-docs.diffblue.com/features/output-codes/working-with-output-codes/working-with-code-e085.md).

# Working with code E085

**E085 - Attempt to compile a test as Groovy**

Diffblue Cover writes test cases by default in `src/test/java` and this can be changed with the `--test-output-dir` option. For Diffblue Cover to run successfully, the produced test files must be compiled by the build system as Java. In particular, some Maven plugins like GMavenPlus, could interfere with Diffblue Cover by attempting to compile the tests as Groovy. Please ensure Diffblue Cover tests are not included in the plugin configuration. An example of a suitable configuration of the GMavenPlus plugin in the POM file of the project is as follows:

```
                <configuration>
                    <testSources>
                        <testSource>
                            <directory>${project.basedir}/src/test/java</directory>
                            <excludes>
                                <exclude>**/*.java</exclude>
                            </excludes>
                            <includes>
                                <include>**/*.groovy</include>
                            </includes>
                        </testSource>
                    </testSources>
                </configuration>
```