Try something else

simpleexample/build.gradle

@@ -26,19 +26,17 @@ javafx {
     // launch debugger using Remote Java Application debug launch configuration
 }
 
-test {
-	// don't run UI test on server (that cannot run javafx)
-	if (project.hasProperty('gitlab-ci')) {
-		exclude 'simpleex.ui/*'
-	}
+sourceSets {
+    main {
+        java {
+			// don't include UI without FxMapControl installed
+			if (project.hasProperty('gitlab-ci')) {
+                exclude 'simpleex.ui/*'
+            }
+        }
+    }
 }
 
-compile {
-	// don't compile UI without FxMapControl installed
-	if (project.hasProperty('gitlab-ci')) {
-		exclude 'simpleex.ui/*'
-	}
-}
 test {
 	// don't run UI test on server (that cannot run javafx)
 	if (project.hasProperty('gitlab-ci')) {