diff --git a/substratevm/src/com.oracle.graal.pointsto.standalone/src/com/oracle/graal/pointsto/standalone/PointsToAnalyzer.java b/substratevm/src/com.oracle.graal.pointsto.standalone/src/com/oracle/graal/pointsto/standalone/PointsToAnalyzer.java
index ed8716cdadc3..8e0a88f521da 100644
--- a/substratevm/src/com.oracle.graal.pointsto.standalone/src/com/oracle/graal/pointsto/standalone/PointsToAnalyzer.java
+++ b/substratevm/src/com.oracle.graal.pointsto.standalone/src/com/oracle/graal/pointsto/standalone/PointsToAnalyzer.java
@@ -306,8 +306,8 @@ public static void main(String[] args) {
     }
 
     protected static void reportException(Throwable e) {
-        System.err.print("Exception:");
-        e.printStackTrace();
+        System.out.print("Exception:");
+        e.printStackTrace(System.out);
     }
 
     public ClassLoader getClassLoader() {
diff --git a/substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisType.java b/substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisType.java
index 42e1d9c44bc5..cbc22e5f721d 100644
--- a/substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisType.java
+++ b/substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisType.java
@@ -449,7 +449,7 @@ public static boolean verifyAssignableTypes(BigBang bb) {
             }
         });
         if (!mismatchedAssignableResults.isEmpty()) {
-            mismatchedAssignableResults.forEach(System.err::println);
+            mismatchedAssignableResults.forEach(System.out::println);
             throw new AssertionError("Verification of all-instantiated type flows failed");
         }
         return true;
@@ -1166,7 +1166,7 @@ public boolean isLocal() {
         try {
             return wrapped.isLocal();
         } catch (InternalError e) {
-            System.err.println("warning: unknown locality of class " + wrapped.getName() + ", assuming class is not local. To remove the warning report an issue " +
+            System.out.println("Warning: unknown locality of class " + wrapped.getName() + ", assuming class is not local. To remove the warning report an issue " +
                             "to the library or language author. The issue is caused by " + wrapped.getName() + " which is not following the naming convention.");
             return false;
         }
diff --git a/substratevm/src/com.oracle.objectfile/src/com/oracle/objectfile/pecoff/PECoffUserDefinedSection.java b/substratevm/src/com.oracle.objectfile/src/com/oracle/objectfile/pecoff/PECoffUserDefinedSection.java
index 4d34aa1ee8a9..7d7c62d564cf 100644
--- a/substratevm/src/com.oracle.objectfile/src/com/oracle/objectfile/pecoff/PECoffUserDefinedSection.java
+++ b/substratevm/src/com.oracle.objectfile/src/com/oracle/objectfile/pecoff/PECoffUserDefinedSection.java
@@ -185,6 +185,6 @@ public void markRelocationSite(int offset, ByteBuffer bb, ObjectFile.RelocationK
      * @param msg warning message that is printed.
      */
     private static void warn(String msg) {
-        System.err.println("Warning: " + msg);
+        System.out.println("Warning: " + msg);
     }
 }
diff --git a/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/NativeImageAgent.java b/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/NativeImageAgent.java
index 2c09b2f1d9a3..addf1ebdd4bd 100644
--- a/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/NativeImageAgent.java
+++ b/substratevm/src/com.oracle.svm.agent/src/com/oracle/svm/agent/NativeImageAgent.java
@@ -402,7 +402,9 @@ protected int onLoadCallback(JNIJavaVM vm, JvmtiEnv jvmti, JvmtiEventCallbacks c
     }
 
     private static void inform(String message) {
+        // Checkstyle: allow System.err
         System.err.println(AGENT_NAME + ": " + message);
+        // Checkstyle: disallow System.err
     }
 
     private static void warn(String message) {
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ConfigurationTool.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ConfigurationTool.java
index a94b9401e174..09b2b66df05b 100644
--- a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ConfigurationTool.java
+++ b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/ConfigurationTool.java
@@ -116,7 +116,7 @@ public static void main(String[] args) {
                     throw new UsageException("Unknown subcommand: " + first);
             }
         } catch (UsageException e) {
-            System.err.println(e.getMessage() + System.lineSeparator() +
+            System.out.println(e.getMessage() + System.lineSeparator() +
                             "Use 'native-image-configure help' for usage.");
             System.exit(2);
         } catch (Exception e) {
@@ -311,7 +311,7 @@ private static void generate(Iterator<String> argsIter, boolean acceptTraceFileA
         }
 
         if (outputCollection.isEmpty()) {
-            System.err.println("Warning: no outputs specified, validating inputs only.");
+            System.out.println("Warning: no outputs specified, validating inputs only.");
         }
         for (URI uri : outputCollection.getReflectConfigPaths()) {
             try (JsonWriter writer = new JsonWriter(Paths.get(uri))) {
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/filters/ModuleFilterTools.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/filters/ModuleFilterTools.java
index 079f50d64ad2..b13f35fb7e2e 100644
--- a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/filters/ModuleFilterTools.java
+++ b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/filters/ModuleFilterTools.java
@@ -58,7 +58,7 @@ public static HierarchyFilterNode generateFromModules(String[] moduleNames, Incl
     private static void checkDependencies(Module module, Set<String> includedModuleNames) {
         for (ModuleDescriptor.Requires require : module.getDescriptor().requires()) {
             if (!includedModuleNames.contains(require.name())) {
-                System.err.println("Warning: dependency missing from input set of modules: " + module.getName() + " -> " + require.name());
+                System.out.println("Warning: dependency missing from input set of modules: " + module.getName() + " -> " + require.name());
                 checkDependencies(module.getLayer().findModule(require.name()).get(), includedModuleNames);
             }
         }
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/AbstractProcessor.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/AbstractProcessor.java
index 57c3c4f3e38e..0288aafd700b 100644
--- a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/AbstractProcessor.java
+++ b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/AbstractProcessor.java
@@ -42,7 +42,7 @@ void setInLivePhase(@SuppressWarnings("unused") boolean live) {
     }
 
     static void logWarning(String warning) {
-        System.err.println("Warning: " + warning);
+        System.out.println("Warning: " + warning);
     }
 
     @SuppressWarnings("unchecked")
diff --git a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java
index 704f46ecd856..dbbcf5cbad05 100644
--- a/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java
+++ b/substratevm/src/com.oracle.svm.configure/src/com/oracle/svm/configure/trace/ReflectionProcessor.java
@@ -271,7 +271,7 @@ public void processEntry(EconomicMap<String, ?> entry, ConfigurationSet configur
                 break;
             }
             default:
-                System.err.println("Unsupported reflection method: " + function);
+                System.out.println("Unsupported reflection method: " + function);
         }
     }
 
diff --git a/substratevm/src/com.oracle.svm.core/.checkstyle_checks.xml b/substratevm/src/com.oracle.svm.core/.checkstyle_checks.xml
index 293f176e4b72..d71556be7e25 100644
--- a/substratevm/src/com.oracle.svm.core/.checkstyle_checks.xml
+++ b/substratevm/src/com.oracle.svm.core/.checkstyle_checks.xml
@@ -54,6 +54,21 @@
       <metadata name="com.atlassw.tools.eclipse.checkstyle.comment" value="Disable Class.getSimpleName calls"/>
     </module>
 
+    <module name="RegexpSinglelineJava">
+      <property name="id" value="systemErr"/>
+      <metadata name="net.sf.eclipsecs.core.comment" value="Disallow calls to System.err."/>
+      <property name="severity" value="error"/>
+      <property name="format" value="System\.err"/>
+      <property name="message" value="Calls to System.err are restricted. Please use logging or System.out instead. (Use &quot;// Checkstyle: allow System.err ... // Checkstyle: disallow System.err&quot; to disable this check.)"/>
+      <property name="ignoreComments" value="true"/>
+    </module>
+    <module name="SuppressionCommentFilter">
+      <property name="offCommentFormat" value="Checkstyle: allow System.err"/>
+      <property name="onCommentFormat" value="Checkstyle: disallow System.err"/>
+      <property name="idFormat" value="systemErr"/>
+      <metadata name="com.atlassw.tools.eclipse.checkstyle.comment" value="Disable System.err calls"/>
+    </module>
+
     <module name="AvoidStarImport">
       <property name="allowClassImports" value="false"/>
       <property name="allowStaticMemberImports" value="false"/>
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/FallbackExecutor.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/FallbackExecutor.java
index decc55655884..c98dac349e62 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/FallbackExecutor.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/FallbackExecutor.java
@@ -135,7 +135,7 @@ private static Path getJavaExecutable() {
     }
 
     private static void showError(String s) {
-        System.err.println("Error: " + s);
+        System.out.println("Error: " + s);
         System.exit(1);
     }
 }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/JavaMainWrapper.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/JavaMainWrapper.java
index e6fb30ca62ca..b704085221e3 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/JavaMainWrapper.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/JavaMainWrapper.java
@@ -147,7 +147,7 @@ private static int runCore0() {
                     System.out.println("Heap dump created at '" + absoluteHeapDumpPath + "'.");
                     return 0;
                 } else {
-                    System.err.println("Unable to dump heap. Heap dumping is only supported for native executables built with `" + VMInspectionOptions.getHeapdumpsCommandArgument() + "`.");
+                    System.out.println("Unable to dump heap. Heap dumping is only supported for native executables built with `" + VMInspectionOptions.getHeapdumpsCommandArgument() + "`.");
                     return 1;
                 }
             }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ConfigurationParser.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ConfigurationParser.java
index 682a3c358345..3f6173e9ca84 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ConfigurationParser.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ConfigurationParser.java
@@ -130,7 +130,7 @@ protected void warnOrFail(String message) {
         if (strictConfiguration) {
             throw new JSONParserException(message);
         } else {
-            System.err.println("Warning: " + message);
+            System.out.println("Warning: " + message);
         }
     }
 
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ReflectionConfigurationParser.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ReflectionConfigurationParser.java
index 471eb18c5056..65c5562518ae 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ReflectionConfigurationParser.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ReflectionConfigurationParser.java
@@ -291,6 +291,6 @@ private static void handleError(String msg, Throwable cause) {
         if (cause != null) {
             message += " Reason: " + formatError(cause) + '.';
         }
-        System.err.println("Warning: " + message);
+        System.out.println("Warning: " + message);
     }
 }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/CEntryPointSnippets.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/CEntryPointSnippets.java
index e99967118b0d..923efe5c35c9 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/CEntryPointSnippets.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/CEntryPointSnippets.java
@@ -344,8 +344,8 @@ private static int initializeIsolate(CEntryPointCreateIsolateParameters paramete
         try {
             RuntimeSupport.executeInitializationHooks();
         } catch (Throwable t) {
-            System.err.println("Uncaught exception while running initialization hooks:");
-            t.printStackTrace();
+            System.out.println("Uncaught exception while running initialization hooks:");
+            t.printStackTrace(System.out);
             CEntryPointActions.leaveTearDownIsolate();
             return CEntryPointErrors.ISOLATE_INITIALIZATION_FAILED;
         }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassLoadingExceptionSupport.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassLoadingExceptionSupport.java
index bc9f8b20712d..a03008f18280 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassLoadingExceptionSupport.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/hub/ClassLoadingExceptionSupport.java
@@ -69,7 +69,7 @@ public static Throwable getExceptionForClass(String className, Throwable origina
     }
 
     private static void terminateUnconfigured(String className) {
-        System.err.println("Missing metadata error: Unable to process Class.forName invocation for class name " + className);
+        System.out.println("Missing metadata error: Unable to process Class.forName invocation for class name " + className);
         System.exit(EXIT_CODE);
     }
 }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/TimeZoneSubstitutions.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/TimeZoneSubstitutions.java
index 45b434926743..b225d88cc882 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/TimeZoneSubstitutions.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/TimeZoneSubstitutions.java
@@ -146,7 +146,7 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String ol
         };
 
         private static void printWarning() {
-            System.err.println("-H:IncludeAllTimeZones and -H:IncludeTimeZones are now deprecated. Native-image includes all timezones" +
+            System.out.println("-H:IncludeAllTimeZones and -H:IncludeTimeZones are now deprecated. Native-image includes all timezones" +
                             " by default.");
         }
     }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrFeature.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrFeature.java
index 405cc7027057..43f8814660d7 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrFeature.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrFeature.java
@@ -115,7 +115,7 @@ public static boolean isInConfiguration(boolean allowPrinting) {
         boolean runtimeEnabled = VMInspectionOptions.hasJfrSupport();
         if (HOSTED_ENABLED && !runtimeEnabled) {
             if (allowPrinting) {
-                System.err.println("Warning: When FlightRecoder is used to profile the image generator, it is also automatically enabled in the native image at run time. " +
+                System.out.println("Warning: When FlightRecoder is used to profile the image generator, it is also automatically enabled in the native image at run time. " +
                                 "This can affect the measurements because it can can make the image larger and image build time longer.");
             }
             runtimeEnabled = true;
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/option/SubstrateOptionsParser.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/option/SubstrateOptionsParser.java
index 62fada7890e8..44a77798f8cb 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/option/SubstrateOptionsParser.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/option/SubstrateOptionsParser.java
@@ -107,7 +107,7 @@ public static boolean parseHostedOption(String optionPrefix, EconomicMap<String,
             if (deprecationMessage != null && !deprecationMessage.isEmpty()) {
                 message += ": " + deprecationMessage;
             }
-            System.err.println(message);
+            System.out.println(message);
         }
         return true;
     }
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/reflect/proxy/DynamicProxySupport.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/reflect/proxy/DynamicProxySupport.java
index 0d6f588b5763..bc4c1f9d6889 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/reflect/proxy/DynamicProxySupport.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/reflect/proxy/DynamicProxySupport.java
@@ -133,7 +133,7 @@ public void addProxyClass(Class<?>... interfaces) {
 
                 return clazz;
             } catch (Throwable t) {
-                System.err.println("Warning: Could not create a proxy class from list of interfaces: " + Arrays.toString(interfaces) + ". Reason: " + t.getMessage());
+                System.out.println("Warning: Could not create a proxy class from list of interfaces: " + Arrays.toString(interfaces) + ". Reason: " + t.getMessage());
                 return t;
             }
         });
diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/thread/JavaThreads.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/thread/JavaThreads.java
index 2c0f772b9fab..d8edf20312f7 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/thread/JavaThreads.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/thread/JavaThreads.java
@@ -237,8 +237,8 @@ public static void dispatchUncaughtException(Thread thread, Throwable throwable)
             }
         } else {
             /* If no uncaught exception handler is present, then just report the throwable. */
-            System.err.print("Exception in thread \"" + Thread.currentThread().getName() + "\" ");
-            throwable.printStackTrace();
+            System.out.print("Exception in thread \"" + Thread.currentThread().getName() + "\" ");
+            throwable.printStackTrace(System.out);
         }
     }
 
diff --git a/substratevm/src/com.oracle.svm.diagnosticsagent/src/com/oracle/svm/diagnosticsagent/NativeImageDiagnosticsAgent.java b/substratevm/src/com.oracle.svm.diagnosticsagent/src/com/oracle/svm/diagnosticsagent/NativeImageDiagnosticsAgent.java
index b14465bfe396..01ba36b70ca9 100644
--- a/substratevm/src/com.oracle.svm.diagnosticsagent/src/com/oracle/svm/diagnosticsagent/NativeImageDiagnosticsAgent.java
+++ b/substratevm/src/com.oracle.svm.diagnosticsagent/src/com/oracle/svm/diagnosticsagent/NativeImageDiagnosticsAgent.java
@@ -191,7 +191,7 @@ private void onClassPrepareCallback(JvmtiEnv jvmti, JNIEnvironment jni, JNIObjec
                     clinitClassMap.put(clinitMethodId.rawValue(), classHandleHolder);
                     check(jvmti.getFunctions().SetBreakpoint().invoke(jvmti, clinitMethodId, 0L));
                 } else {
-                    System.err.println("Trace class initialization requested for " + className + " but the class has not been instrumented with <clinit>.");
+                    System.out.println("Trace class initialization requested for " + className + " but the class has not been instrumented with <clinit>.");
                 }
             }
             if (advisor.shouldTraceObjectInstantiation(className)) {
@@ -211,7 +211,7 @@ private void setConstructorBreakpointsForClass(JvmtiEnv jvmti, JNIEnvironment jn
             }
         } else {
             /* This should never happen. */
-            System.err.println("Trace object instantiation requested for " + className + " but the class has no constructors.");
+            System.out.println("Trace object instantiation requested for " + className + " but the class has no constructors.");
         }
     }
 
@@ -396,8 +396,8 @@ private byte[] maybeInstrumentClassWithClinit(String clazzName, byte[] clazzData
             return writer.toByteArray();
         } catch (Throwable e) {
             String targetClazzName = clazzName != null ? clazzName : "<unknown class>";
-            System.err.println("[native-image-diagnostics-agent] Failed to instrument class " + targetClazzName + ": ");
-            e.printStackTrace(System.err);
+            System.out.println("[native-image-diagnostics-agent] Failed to instrument class " + targetClazzName + ": ");
+            e.printStackTrace(System.out);
             return null;
         }
     }
diff --git a/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java b/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
index bdee4637071c..ab2cb5b39c59 100644
--- a/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
+++ b/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
@@ -1415,10 +1415,10 @@ private static void performBuild(BuildConfiguration config, Function<BuildConfig
         try {
             build(config, nativeImageProvider);
         } catch (NativeImageError e) {
-            NativeImage.show(System.err::println, "Error: " + e.getMessage());
+            NativeImage.show(System.out::println, "Error: " + e.getMessage());
             Throwable cause = e.getCause();
             while (cause != null) {
-                NativeImage.show(System.err::println, "Caused by: " + cause);
+                NativeImage.show(System.out::println, "Caused by: " + cause);
                 cause = cause.getCause();
             }
             if (config.getBuildArgs().contains("--verbose")) {
@@ -1734,7 +1734,7 @@ void showMessagePart(String message) {
     }
 
     public static void showWarning(String message) {
-        show(System.err::println, "Warning: " + message);
+        show(System.out::println, "Warning: " + message);
     }
 
     @SuppressWarnings("serial")
diff --git a/substratevm/src/com.oracle.svm.hosted/.checkstyle_checks.xml b/substratevm/src/com.oracle.svm.hosted/.checkstyle_checks.xml
index d05cf955ff22..5e33a191507c 100644
--- a/substratevm/src/com.oracle.svm.hosted/.checkstyle_checks.xml
+++ b/substratevm/src/com.oracle.svm.hosted/.checkstyle_checks.xml
@@ -20,6 +20,21 @@
       <metadata name="com.atlassw.tools.eclipse.checkstyle.comment" value="Disable Class.getSimpleName calls"/>
     </module>
 
+    <module name="RegexpSinglelineJava">
+      <property name="id" value="systemErr"/>
+      <metadata name="net.sf.eclipsecs.core.comment" value="Disallow calls to System.err."/>
+      <property name="severity" value="error"/>
+      <property name="format" value="System\.err"/>
+      <property name="message" value="Calls to System.err are restricted. Please use logging or System.out instead. (Use &quot;// Checkstyle: allow System.err ... // Checkstyle: disallow System.err&quot; to disable this check.)"/>
+      <property name="ignoreComments" value="true"/>
+    </module>
+    <module name="SuppressionCommentFilter">
+      <property name="offCommentFormat" value="Checkstyle: allow System.err"/>
+      <property name="onCommentFormat" value="Checkstyle: disallow System.err"/>
+      <property name="idFormat" value="systemErr"/>
+      <metadata name="com.atlassw.tools.eclipse.checkstyle.comment" value="Disable System.err calls"/>
+    </module>
+
     <module name="AvoidStarImport">
       <property name="allowClassImports" value="false"/>
       <property name="allowStaticMemberImports" value="false"/>
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ConfigurationTypeResolver.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ConfigurationTypeResolver.java
index 32a650fc7db6..91177c2fec6a 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ConfigurationTypeResolver.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ConfigurationTypeResolver.java
@@ -53,7 +53,7 @@ private Class<?> resolveType(String typeName, boolean warn) {
         }
         TypeResult<Class<?>> typeResult = classLoader.findClass(name);
         if (warn && !typeResult.isPresent()) {
-            System.err.println("Warning: Could not resolve " + name + " for " + configurationType + ".");
+            System.out.println("Warning: Could not resolve " + name + " for " + configurationType + ".");
         }
         return typeResult.get();
     }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/DeadlockWatchdog.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/DeadlockWatchdog.java
index a67228d3ab10..92c7b8306ea8 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/DeadlockWatchdog.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/DeadlockWatchdog.java
@@ -76,19 +76,19 @@ void watchdogThread() {
         while (!stopped) {
             long now = System.currentTimeMillis();
             if (enabled && now >= nextDeadline) {
-                System.err.println();
-                System.err.println("=== Image generator watchdog detected no activity. This can be a sign of a deadlock during image building. Dumping all stack traces. Current time: " + new Date());
+                System.out.println();
+                System.out.println("=== Image generator watchdog detected no activity. This can be a sign of a deadlock during image building. Dumping all stack traces. Current time: " + new Date());
                 threadDump();
                 Runtime runtime = Runtime.getRuntime();
                 final long heapSizeUnit = 1024 * 1024;
                 long usedHeapSize = runtime.totalMemory() / heapSizeUnit;
                 long freeHeapSize = runtime.freeMemory() / heapSizeUnit;
                 long maximumHeapSize = runtime.maxMemory() / heapSizeUnit;
-                System.err.printf("=== Memory statistics (in MB):%n=== Used heap size: %d%n=== Free heap size: %d%n=== Maximum heap size: %d%n", usedHeapSize, freeHeapSize, maximumHeapSize);
-                System.err.flush();
+                System.out.printf("=== Memory statistics (in MB):%n=== Used heap size: %d%n=== Free heap size: %d%n=== Maximum heap size: %d%n", usedHeapSize, freeHeapSize, maximumHeapSize);
+                System.out.flush();
 
                 if (watchdogExitOnTimeout) {
-                    System.err.println("=== Image generator watchdog is aborting image generation. To configure the watchdog, use the options " +
+                    System.out.println("=== Image generator watchdog is aborting image generation. To configure the watchdog, use the options " +
                                     SubstrateOptionsParser.commandArgument(SubstrateOptions.DeadlockWatchdogInterval, Integer.toString(watchdogInterval), null) + " and " +
                                     SubstrateOptionsParser.commandArgument(SubstrateOptions.DeadlockWatchdogExitOnTimeout, "+", null));
                     /*
@@ -125,7 +125,7 @@ private static void threadDump() {
             printThreadInfo(ti);
             printLockInfo(ti.getLockedSynchronizers());
         }
-        System.err.println();
+        System.out.println();
     }
 
     private static void printThreadInfo(ThreadInfo ti) {
@@ -139,33 +139,33 @@ private static void printThreadInfo(ThreadInfo ti) {
         if (ti.isInNative()) {
             sb.append(" (running in native)");
         }
-        System.err.println(sb.toString());
+        System.out.println(sb.toString());
 
         if (ti.getLockOwnerName() != null) {
-            System.err.println("      owned by " + ti.getLockOwnerName() + " Id=" + ti.getLockOwnerId());
+            System.out.println("      owned by " + ti.getLockOwnerName() + " Id=" + ti.getLockOwnerId());
         }
 
         StackTraceElement[] stacktrace = ti.getStackTrace();
         MonitorInfo[] monitors = ti.getLockedMonitors();
         for (int i = 0; i < stacktrace.length; i++) {
             StackTraceElement ste = stacktrace[i];
-            System.err.println("    at " + ste.toString());
+            System.out.println("    at " + ste.toString());
             for (MonitorInfo mi : monitors) {
                 if (mi.getLockedStackDepth() == i) {
-                    System.err.println("      - locked " + mi);
+                    System.out.println("      - locked " + mi);
                 }
             }
         }
-        System.err.println();
+        System.out.println();
     }
 
     private static void printLockInfo(LockInfo[] locks) {
         if (locks.length > 0) {
-            System.err.println("    Locked synchronizers: count = " + locks.length);
+            System.out.println("    Locked synchronizers: count = " + locks.length);
             for (LockInfo li : locks) {
-                System.err.println("      - " + li);
+                System.out.println("      - " + li);
             }
-            System.err.println();
+            System.out.println();
         }
     }
 }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/Log4ShellFeature.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/Log4ShellFeature.java
index 53e5fcc9e25f..c5af2ea75d53 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/Log4ShellFeature.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/Log4ShellFeature.java
@@ -62,7 +62,7 @@ public class Log4ShellFeature implements InternalFeature {
     private static final Set<String> targetMethods = Set.of("debug", "error", "fatal", "info", "log", "trace", "warn");
 
     private static void warn(String warning) {
-        System.err.println(warning);
+        System.out.println(warning);
     }
 
     private static Optional<String> getPomVersion(Class<?> log4jClass) {
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java
index f02f9823bf3c..dd7ca217fc60 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java
@@ -700,7 +700,7 @@ private void loadClassesFromPath(URI container, Path root, Path excludeRoot, Set
             boolean useFilter = root.equals(excludeRoot);
             if (useFilter) {
                 String excludesStr = excludes.stream().map(Path::toString).collect(Collectors.joining(", "));
-                System.err.println("Warning: Using directory " + excludeRoot + " on classpath is discouraged." +
+                System.out.println("Warning: Using directory " + excludeRoot + " on classpath is discouraged." +
                                 " Reading classes/resources from directories " + excludesStr + " will be suppressed.");
             }
             FileVisitor<Path> visitor = new SimpleFileVisitor<>() {
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageGeneratorRunner.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageGeneratorRunner.java
index 8c412ba4f92a..a33b6753e2fc 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageGeneratorRunner.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageGeneratorRunner.java
@@ -445,7 +445,7 @@ private int buildImage(ImageClassLoader classLoader) {
             }
 
             if (pee.getExceptions().size() > 1) {
-                System.err.println(pee.getExceptions().size() + " fatal errors detected:");
+                System.out.println(pee.getExceptions().size() + " fatal errors detected:");
             }
             for (Throwable exception : pee.getExceptions()) {
                 NativeImageGeneratorRunner.reportFatalError(exception);
@@ -537,7 +537,7 @@ public static String getJavaVersion() {
      * @param e error to be reported.
      */
     protected static void reportFatalError(Throwable e) {
-        System.err.print("Fatal error: ");
+        System.out.print("Fatal error: ");
         e.printStackTrace();
     }
 
@@ -548,7 +548,7 @@ protected static void reportFatalError(Throwable e) {
      * @param msg message to report.
      */
     protected static void reportFatalError(Throwable e, String msg) {
-        System.err.print("Fatal error: " + msg);
+        System.out.print("Fatal error: " + msg);
         e.printStackTrace();
     }
 
@@ -558,7 +558,7 @@ protected static void reportFatalError(Throwable e, String msg) {
      * @param msg error message that is printed.
      */
     public static void reportUserError(String msg) {
-        System.err.println("Error: " + msg);
+        System.out.println("Error: " + msg);
     }
 
     /**
@@ -603,7 +603,7 @@ private static void info(String msg) {
      * @param msg warning message that is printed.
      */
     private static void warn(String msg) {
-        System.err.println("Warning: " + msg);
+        System.out.println("Warning: " + msg);
     }
 
     public int build(ImageClassLoader imageClassLoader) {
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageSystemIOWrappers.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageSystemIOWrappers.java
index 77e2a7f80744..b28a1acdf481 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageSystemIOWrappers.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageSystemIOWrappers.java
@@ -40,13 +40,17 @@ public class NativeImageSystemIOWrappers {
 
     NativeImageSystemIOWrappers() {
         outWrapper = new StdioWrapper(System.out);
+        // Checkstyle: allow System.err
         errWrapper = new StdioWrapper(System.err);
+        // Checkstyle: disallow System.err
     }
 
     void verifySystemOutErrReplacement() {
         String format = "%s was changed during image building. This is not allowed.";
         UserError.guarantee(System.out == outWrapper, format, "System.out");
+        // Checkstyle: allow System.err
         UserError.guarantee(System.err == errWrapper, format, "System.err");
+        // Checkstyle: disallow System.err
     }
 
     void replaceSystemOutErr() {
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/c/libc/HostedMuslLibC.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/c/libc/HostedMuslLibC.java
index 8c65c19e18a1..dce1f1f76561 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/c/libc/HostedMuslLibC.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/c/libc/HostedMuslLibC.java
@@ -51,7 +51,7 @@ public boolean requiresLibCSpecificStaticJDKLibraries() {
     @Override
     public void checkIfLibCSupported() {
         if (!SubstrateOptions.StaticExecutable.getValue()) {
-            System.err.println("Warning: Cross-compiling a musl-based native-image that is not an executable is an experimental feature!" +
+            System.out.println("Warning: Cross-compiling a musl-based native-image that is not an executable is an experimental feature!" +
                             "If omitting --static wasn't the intention, then --static should be used when compiling with --libc=musl");
         }
     }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/classinitialization/ClassInitializationFeature.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/classinitialization/ClassInitializationFeature.java
index a8f6d3275819..0247454db160 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/classinitialization/ClassInitializationFeature.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/classinitialization/ClassInitializationFeature.java
@@ -190,7 +190,7 @@ public void afterAnalysis(AfterAnalysisAccess access) {
                                 .map(Class::getTypeName)
                                 .collect(Collectors.toList());
                 if (!unspecifiedClasses.isEmpty()) {
-                    System.err.println("The following classes have unspecified initialization policy:" + System.lineSeparator() + String.join(System.lineSeparator(), unspecifiedClasses));
+                    System.out.println("The following classes have unspecified initialization policy:" + System.lineSeparator() + String.join(System.lineSeparator(), unspecifiedClasses));
                     UserError.abort("To fix the error either specify the initialization policy for given classes or set %s",
                                     SubstrateOptionsParser.commandArgument(ClassInitializationOptions.AssertInitializationSpecifiedForAllClasses, "-"));
                 }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/meta/TypeCheckBuilder.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/meta/TypeCheckBuilder.java
index d80de19f4573..b4ba4803f44c 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/meta/TypeCheckBuilder.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/meta/TypeCheckBuilder.java
@@ -1746,7 +1746,7 @@ static boolean compareTypeIDResults(List<HostedType> types) {
                     }
                 });
                 if (!mismatchedTypes.isEmpty()) {
-                    mismatchedTypes.forEach(System.err::println);
+                    mismatchedTypes.forEach(System.out::println);
                     throw new AssertionError("Verification of type assignment failed");
                 }
             }
diff --git a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/reflect/serialize/SerializationFeature.java b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/reflect/serialize/SerializationFeature.java
index ac3b4a973d19..cce4d02bca1b 100644
--- a/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/reflect/serialize/SerializationFeature.java
+++ b/substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/reflect/serialize/SerializationFeature.java
@@ -259,7 +259,7 @@ public void beforeCompilation(BeforeCompilationAccess access) {
     }
 
     static void warn(String str) {
-        System.err.println("Warning: " + str);
+        System.out.println("Warning: " + str);
     }
 }
 
diff --git a/substratevm/src/org.graalvm.polyglot.nativeapi/src/org/graalvm/polyglot/nativeapi/PolyglotNativeAPIFeature.java b/substratevm/src/org.graalvm.polyglot.nativeapi/src/org/graalvm/polyglot/nativeapi/PolyglotNativeAPIFeature.java
index b7a65d588c14..8eb6a8da51a0 100644
--- a/substratevm/src/org.graalvm.polyglot.nativeapi/src/org/graalvm/polyglot/nativeapi/PolyglotNativeAPIFeature.java
+++ b/substratevm/src/org.graalvm.polyglot.nativeapi/src/org/graalvm/polyglot/nativeapi/PolyglotNativeAPIFeature.java
@@ -69,15 +69,14 @@ public void afterImageWrite(AfterImageWriteAccess access) {
             // on Darwin, change the `id` install name
             String id = System.getProperty("org.graalvm.polyglot.install_name_id");
             if (id == null) {
-                String msg = String.format("Warning: no id passed through `org.graalvm.polyglot.install_name_id`:" +
-                                "\n%s might include its absolute path as id (see man install_name_tool)", imagePath);
-                System.err.println(msg);
+                System.out.printf("Warning: no id passed through `org.graalvm.polyglot.install_name_id`:%n" +
+                                "%s might include its absolute path as id (see man install_name_tool)%n", imagePath);
             } else {
                 List<String> command = Arrays.asList("install_name_tool", "-id", id, imagePath.toString());
                 try {
                     int exitCode = FileUtils.executeCommand(command);
                     if (exitCode != 0) {
-                        System.err.printf("Failed to set `id` install name. install_name_tool exited with code %d%n", exitCode);
+                        System.out.printf("Failed to set `id` install name. install_name_tool exited with code %d%n", exitCode);
                     }
                 } catch (IOException e) {
                     throw new RuntimeException(e);