Hi Daniel, I think I have found a bug in the antlr4 AstBuilder class.
Add this line: import groovy.transform.CompileStatic before this one in a GString template: https://github.com/melix/groovy-core/blob/d9656842908acb403599cf574f509aea2737be47/subprojects/groovy-groovydoc/src/main/resources/org/codehaus/groovy/tools/groovydoc/gstringTemplates/classLevel/classDocName.html#L27 And run GroovyDocToolTest. Some tests will fail with: java.lang.ClassCastException: org.codehaus.groovy.ast.ImportNode cannot be cast to org.codehaus.groovy.ast.stmt.Statement at org.apache.groovy.parser.antlr4.AstBuilder.visitBlockStatement(AstBuilder.java:4074) at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) at org.apache.groovy.parser.antlr4.AstBuilder.visitBlockStatements(AstBuilder.java:4058) at org.apache.groovy.parser.antlr4.AstBuilder.visitBlockStatementsOpt(AstBuilder.java:4045) at org.apache.groovy.parser.antlr4.AstBuilder.visitClosure(AstBuilder.java:3715) at org.apache.groovy.parser.antlr4.AstBuilder.visitClosurePrmrAlt(AstBuilder.java:3120) at org.apache.groovy.parser.antlr4.AstBuilder.visitClosurePrmrAlt(AstBuilder.java:356)