diff -urEbwB groovy-core-GROOVY_1_8_9.orig/build.xml groovy-core-GROOVY_1_8_9/build.xml
--- groovy-core-GROOVY_1_8_9.orig/build.xml	2013-02-15 09:42:29.000000000 +0100
+++ groovy-core-GROOVY_1_8_9/build.xml	2022-03-22 20:27:42.099395524 +0100
@@ -180,7 +180,7 @@
             <exclude name="groovy/ui/**/*.java"/>
         </javac>
         <java classname="org.codehaus.groovy.tools.DgmConverter"
-              fork="yes"
+              fork="no"
               failonerror="true">
             <classpath>
                 <pathelement path="${mainClassesDirectory}"/>
@@ -194,7 +194,7 @@
 
     <target name="-stagedcompile-groovy" depends="-initGroovyc">
         <groovyc srcdir="${mainSourcePath}" destdir="${mainClassesDirectory}" 
-                 fork="true" stacktrace="true"
+                 fork="false" stacktrace="true"
                  memorymaximumsize="${groovycMain_mx}">
             <classpath>
                 <pathelement path="${mainClassesDirectory}"/>