setup:
        buildFile.text = """
            apply plugin: 'eclipse'
            eclipse {
                project {
                    file {
                        whenMerged {
                            ${server.callFromBuild("waiting")}
                        }
                    }
                }
            }
        """.stripIndent()

                it.buildCommands = [new BuildCommand('buildCommandBefore', [:])]
                it.linkedResources += new Link('linkToDelete2', '2', null, '../some-directory')
            }
            file.whenMerged {
                it.natures += 'nature.c'
                it.buildCommands << new BuildCommand('buildCommandAfter', [:])
                it.linkedResources = [new Link('linkAfter', '2', null, '../some-directory')]

                        plusConfigurations.addAll(component.getLibConfigurations());
                    }
                });

                model.getClasspath().getFile().whenMerged(new Action<Classpath>() {
                    @Override
                    public void execute(Classpath classpath) {
                        new WtpClasspathAttributeSupport(project, model).enhance(classpath);

apply plugin: "idea"

idea {
    module {
        excludeDirs = [project.file('folderThatIsExcludedNow')] as Set
        iml {
            beforeMerged { it.excludeFolders.clear() }
            whenMerged   { it.jdkName = '1.33'   }
        }
    }
}
''')
        //then
        def iml = getFile([:], 'root.iml').text
        assert iml.contains('folderThatIsExcludedNow')

        testConfigurations = [configuration.myTestConfiguration]
    }
}
```

Alternatively, you can adjust or remove classpath attributes in the `eclipse.classpath.file.whenMerged { }` block.

==== Signing plugin defaults to `gpg` instead of `gpg2` when using the GPG command

Method <org.gradle.plugins.ide.api.FileContentMerger.whenMerged(groovy.lang.Closure)> has arguments/return type groovy.lang.Closure that is not Gradle public API or primitive or built-in JDK classes or Kotlin classes in (FileContentMerger.java:0)