Try using -Ymagic-offset-header to fixup line numbers

libs/javalib/src/mill/javalib/SemanticDbJavaModule.scala

@@ -236,7 +236,7 @@ object SemanticDbJavaModule extends ExternalModule with CoursierModule {
     )
   }
 
-  private val userCodeStartMarker = "//SOURCECODE_ORIGINAL_CODE_START_MARKER"
+  private val userCodeStartMarker = "///SOURCE_CODE_START"
 
   private def postProcessed(
       generatedSourceSemdb: os.Path,
@@ -255,7 +255,7 @@ object SemanticDbJavaModule extends ExternalModule with CoursierModule {
       val generatedSource = sourceroot / generatedSourceSubPath
       val generatedSourceLines = os.read.lines(generatedSource)
       val source = generatedSourceLines
-        .collectFirst { case s"//SOURCECODE_ORIGINAL_FILE_PATH=$rest" => os.Path(rest.trim) }
+        .collectFirst { case s"///SOURCE_CODE_START:$rest" => os.Path(rest.trim) }
         .getOrElse {
           sys.error(s"Cannot get original source from generated source $generatedSource")
         }

libs/javalib/worker/src/mill/javalib/zinc/ZincWorker.scala

@@ -394,13 +394,12 @@ class ZincWorker(
 
     def mkNewReporter(mapper: (xsbti.Position => xsbti.Position) | Null) = reporter match {
       case None =>
-        new ManagedLoggedReporter(maxErrors, logger) with RecordingReporter
-          with TransformingReporter(ctx.logPromptColored, mapper) {}
+        new ManagedLoggedReporter(maxErrors, logger) with RecordingReporter {}
+
       case Some(forwarder) =>
         new ManagedLoggedReporter(maxErrors, logger)
           with ForwardingReporter(forwarder)
-          with RecordingReporter
-          with TransformingReporter(ctx.logPromptColored, mapper) {}
+          with RecordingReporter {}
     }
     val analysisMap0 = upstreamCompileOutput.map(c => c.classes.path -> c.analysisFile).toMap
 
@@ -455,8 +454,8 @@ class ZincWorker(
         scalacOptions
     }
 
-    val (originalSourcesMap, posMapperOpt) = PositionMapper.create(virtualSources)
-    val newReporter = mkNewReporter(posMapperOpt.orNull)
+//    val (originalSourcesMap, posMapperOpt) = PositionMapper.create(virtualSources)
+    val newReporter = mkNewReporter(null)
 
     val inputs = incrementalCompiler.inputs(
       classpath = classpath,
@@ -524,8 +523,8 @@ class ZincWorker(
       for (rep <- reporter) {
         for (f <- sources) {
           rep.fileVisited(f.toNIO)
-          for (f0 <- originalSourcesMap.get(f))
-            rep.fileVisited(f0.toNIO)
+//          for (f0 <- originalSourcesMap.get(f))
+//            rep.fileVisited(f0.toNIO)
         }
         rep.finish()
       }