Consistently return non-zero exit codes for jarmode failures

Update jar mode launchers to catch all exceptions and return a non-zero
exit code. This refinement also allows us to consolidate the existing
error reporting logic to a central locations. Modes that wish to report
a simple error rather than a full stacktrace can throw the newly
introduced `JarModeErrorException`.

Fixes gh-43435

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/main/java/org/springframework/boot/jarmode/tools/ExtractCommand.java

@@ -43,7 +43,7 @@ import java.util.zip.ZipInputStream;
 
 import org.springframework.boot.jarmode.tools.JarStructure.Entry;
 import org.springframework.boot.jarmode.tools.JarStructure.Entry.Type;
-import org.springframework.boot.jarmode.tools.Layers.LayersNotEnabledException;
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
 import org.springframework.util.Assert;
 import org.springframework.util.StreamUtils;
 import org.springframework.util.StringUtils;
@@ -118,12 +118,6 @@ class ExtractCommand extends Command {
 		catch (IOException ex) {
 			throw new UncheckedIOException(ex);
 		}
-		catch (LayersNotEnabledException ex) {
-			printError(out, "Layers are not enabled");
-		}
-		catch (AbortException ex) {
-			printError(out, ex.getMessage());
-		}
 	}
 
 	private static void checkDirectoryIsEmpty(Map<Option, String> options, File destination) {
@@ -134,11 +128,11 @@ class ExtractCommand extends Command {
 			return;
 		}
 		if (!destination.isDirectory()) {
-			throw new AbortException(destination.getAbsoluteFile() + " already exists and is not a directory");
+			throw new JarModeErrorException(destination.getAbsoluteFile() + " already exists and is not a directory");
 		}
 		File[] files = destination.listFiles();
 		if (files != null && files.length > 0) {
-			throw new AbortException(destination.getAbsoluteFile() + " already exists and is not empty");
+			throw new JarModeErrorException(destination.getAbsoluteFile() + " already exists and is not empty");
 		}
 	}
 
@@ -147,18 +141,13 @@ class ExtractCommand extends Command {
 		try (ZipInputStream stream = new ZipInputStream(new FileInputStream(file))) {
 			ZipEntry entry = stream.getNextEntry();
 			if (entry == null) {
-				throw new AbortException(
+				throw new JarModeErrorException(
 						"File '%s' is not compatible; ensure jar file is valid and launch script is not enabled"
 							.formatted(file));
 			}
 		}
 	}
 
-	private void printError(PrintStream out, String message) {
-		out.println("Error: " + message);
-		out.println();
-	}
-
 	private void extractLibraries(FileResolver fileResolver, JarStructure jarStructure, Map<Option, String> options)
 			throws IOException {
 		String librariesDirectory = getLibrariesDirectory(options);
@@ -494,12 +483,4 @@ class ExtractCommand extends Command {
 
 	}
 
-	private static final class AbortException extends RuntimeException {
-
-		AbortException(String message) {
-			super(message);
-		}
-
-	}
-
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/main/java/org/springframework/boot/jarmode/tools/Layers.java

@@ -19,6 +19,8 @@ package org.springframework.boot.jarmode.tools;
 import java.util.Iterator;
 import java.util.zip.ZipEntry;
 
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
+
 /**
  * Provides information about the jar layers.
  *
@@ -62,22 +64,13 @@ interface Layers extends Iterable<String> {
 	 * Return a {@link Layers} instance for the currently running application.
 	 * @param context the command context
 	 * @return a new layers instance
-	 * @throws LayersNotEnabledException if layers are not enabled
 	 */
 	static Layers get(Context context) {
 		IndexedLayers indexedLayers = IndexedLayers.get(context);
 		if (indexedLayers == null) {
-			throw new LayersNotEnabledException();
+			throw new JarModeErrorException("Layers are not enabled");
 		}
 		return indexedLayers;
 	}
 
-	final class LayersNotEnabledException extends RuntimeException {
-
-		LayersNotEnabledException() {
-			super("Layers not enabled: Failed to load layer index file");
-		}
-
-	}
-
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/main/java/org/springframework/boot/jarmode/tools/ListLayersCommand.java

@@ -20,8 +20,6 @@ import java.io.PrintStream;
 import java.util.List;
 import java.util.Map;
 
-import org.springframework.boot.jarmode.tools.Layers.LayersNotEnabledException;
-
 /**
  * The {@code 'list-layers'} tools command.
  *
@@ -38,22 +36,12 @@ class ListLayersCommand extends Command {
 
 	@Override
 	void run(PrintStream out, Map<Option, String> options, List<String> parameters) {
-		try {
-			Layers layers = Layers.get(this.context);
-			printLayers(out, layers);
-		}
-		catch (LayersNotEnabledException ex) {
-			printError(out, "Layers are not enabled");
-		}
+		Layers layers = Layers.get(this.context);
+		printLayers(out, layers);
 	}
 
 	void printLayers(PrintStream out, Layers layers) {
 		layers.forEach(out::println);
 	}
 
-	private void printError(PrintStream out, String message) {
-		out.println("Error: " + message);
-		out.println();
-	}
-
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/ExtractCommandTests.java

@@ -32,7 +32,10 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
+
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
@@ -172,8 +175,8 @@ class ExtractCommandTests extends AbstractJarModeTests {
 			try (FileWriter writer = new FileWriter(file)) {
 				writer.write("text");
 			}
-			TestPrintStream out = run(file);
-			assertThat(out).contains("is not compatible; ensure jar file is valid and launch script is not enabled");
+			assertThatExceptionOfType(JarModeErrorException.class).isThrownBy(() -> run(file))
+				.withMessageContaining("is not compatible; ensure jar file is valid and launch script is not enabled");
 		}
 
 		@Test
@@ -181,8 +184,9 @@ class ExtractCommandTests extends AbstractJarModeTests {
 			File destination = file("out");
 			Files.createDirectories(destination.toPath());
 			Files.createFile(new File(destination, "file.txt").toPath());
-			TestPrintStream out = run(ExtractCommandTests.this.archive, "--destination", destination.getAbsolutePath());
-			assertThat(out).contains("already exists and is not empty");
+			assertThatExceptionOfType(JarModeErrorException.class)
+				.isThrownBy(() -> run(ExtractCommandTests.this.archive, "--destination", destination.getAbsolutePath()))
+				.withMessageContaining("already exists and is not empty");
 		}
 
 		@Test
@@ -266,10 +270,10 @@ class ExtractCommandTests extends AbstractJarModeTests {
 		}
 
 		@Test
-		void printErrorIfLayersAreNotEnabled() throws IOException {
+		void failsIfLayersAreNotEnabled() throws IOException {
 			File archive = createArchive();
-			TestPrintStream out = run(archive, "--layers");
-			assertThat(out).hasSameContentAsResource("ExtractCommand-printErrorIfLayersAreNotEnabled.txt");
+			assertThatExceptionOfType(JarModeErrorException.class).isThrownBy(() -> run(archive, "--layers"))
+				.withMessage("Layers are not enabled");
 		}
 
 	}
@@ -318,10 +322,11 @@ class ExtractCommandTests extends AbstractJarModeTests {
 		}
 
 		@Test
-		void printErrorIfLayersAreNotEnabled() throws IOException {
+		void failsIfLayersAreNotEnabled() throws IOException {
 			File archive = createArchive();
-			TestPrintStream out = run(archive, "--launcher", "--layers");
-			assertThat(out).hasSameContentAsResource("ExtractCommand-printErrorIfLayersAreNotEnabled.txt");
+			assertThatExceptionOfType(JarModeErrorException.class)
+				.isThrownBy(() -> run(archive, "--launcher", "--layers"))
+				.withMessage("Layers are not enabled");
 		}
 
 		@Test

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/ExtractLayersCommandTests.java

@@ -42,10 +42,12 @@ import org.junit.jupiter.api.io.TempDir;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.mockito.BDDMockito.given;
 
@@ -146,8 +148,9 @@ class ExtractLayersCommandTests {
 		}
 		given(this.context.getArchiveFile()).willReturn(file);
 		try (TestPrintStream out = new TestPrintStream(this)) {
-			this.command.run(out, Collections.emptyMap(), Collections.emptyList());
-			assertThat(out).contains("is not compatible");
+			assertThatExceptionOfType(JarModeErrorException.class)
+				.isThrownBy(() -> this.command.run(out, Collections.emptyMap(), Collections.emptyList()))
+				.withMessageContaining("is not compatible");
 		}
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/ListLayersCommandTests.java

@@ -22,7 +22,10 @@ import java.util.jar.Manifest;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
+
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link ListLayersCommand}.
@@ -39,9 +42,9 @@ class ListLayersCommandTests extends AbstractJarModeTests {
 	}
 
 	@Test
-	void shouldPrintErrorWhenLayersAreNotEnabled() throws IOException {
-		TestPrintStream out = run(createArchive());
-		assertThat(out).hasSameContentAsResource("list-layers-output-layers-disabled.txt");
+	void shouldFailWhenLayersAreNotEnabled() {
+		assertThatExceptionOfType(JarModeErrorException.class).isThrownBy(() -> run(createArchive()))
+			.withMessage("Layers are not enabled");
 	}
 
 	private TestPrintStream run(File archive) {

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/resources/org/springframework/boot/jarmode/tools/ExtractCommand-printErrorIfLayersAreNotEnabled.txt

@@ -1,2 +0,0 @@
-Error: Layers are not enabled
-

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/resources/org/springframework/boot/jarmode/tools/list-layers-output-layers-disabled.txt

@@ -1,2 +0,0 @@
-Error: Layers are not enabled
-

spring-boot-project/spring-boot-tools/spring-boot-loader-classic/src/main/java/org/springframework/boot/loader/jarmode/JarMode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,7 +36,8 @@ public interface JarMode {
 	 * Run the jar in the given mode.
 	 * @param mode the mode to use
 	 * @param args any program arguments
+	 * @throws JarModeErrorException on an error that should print a simple error message
 	 */
-	void run(String mode, String[] args);
+	void run(String mode, String[] args) throws JarModeErrorException;
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader-classic/src/main/java/org/springframework/boot/loader/jarmode/JarModeErrorException.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.loader.jarmode;
+
+/**
+ * Simple {@link RuntimeException} used to fail the jar mode with a simple printed error
+ * message.
+ *
+ * @author Phillip Webb
+ * @since 3.3.7
+ */
+public class JarModeErrorException extends RuntimeException {
+
+	public JarModeErrorException(String message) {
+		super(message);
+	}
+
+	public JarModeErrorException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-loader-classic/src/main/java/org/springframework/boot/loader/jarmode/JarModeLauncher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,11 +31,31 @@ public final class JarModeLauncher {
 
 	static final String DISABLE_SYSTEM_EXIT = JarModeLauncher.class.getName() + ".DISABLE_SYSTEM_EXIT";
 
+	static final String SUPPRESSED_SYSTEM_EXIT_CODE = JarModeLauncher.class.getName() + ".SUPPRESSED_SYSTEM_EXIT_CODE";
+
 	private JarModeLauncher() {
 	}
 
 	public static void main(String[] args) {
 		String mode = System.getProperty("jarmode");
+		boolean disableSystemExit = Boolean.getBoolean(DISABLE_SYSTEM_EXIT);
+		try {
+			runJarMode(mode, args);
+			if (disableSystemExit) {
+				System.setProperty(SUPPRESSED_SYSTEM_EXIT_CODE, "0");
+			}
+		}
+		catch (Throwable ex) {
+			printError(ex);
+			if (disableSystemExit) {
+				System.setProperty(SUPPRESSED_SYSTEM_EXIT_CODE, "1");
+				return;
+			}
+			System.exit(1);
+		}
+	}
+
+	private static void runJarMode(String mode, String[] args) {
 		List<JarMode> candidates = SpringFactoriesLoader.loadFactories(JarMode.class,
 				ClassUtils.getDefaultClassLoader());
 		for (JarMode candidate : candidates) {
@@ -44,10 +64,17 @@ public final class JarModeLauncher {
 				return;
 			}
 		}
-		System.err.println("Unsupported jarmode '" + mode + "'");
-		if (!Boolean.getBoolean(DISABLE_SYSTEM_EXIT)) {
-			System.exit(1);
+		throw new JarModeErrorException("Unsupported jarmode '" + mode + "'");
+	}
+
+	private static void printError(Throwable ex) {
+		if (ex instanceof JarModeErrorException) {
+			String message = ex.getMessage();
+			System.err.println("Error: " + message);
+			System.err.println();
+			return;
 		}
+		ex.printStackTrace();
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader-classic/src/main/java/org/springframework/boot/loader/jarmode/TestJarMode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,12 @@ class TestJarMode implements JarMode {
 	@Override
 	public void run(String mode, String[] args) {
 		System.out.println("running in " + mode + " jar mode " + Arrays.asList(args));
+		if (args.length > 0 && "error".equals(args[0])) {
+			throw new JarModeErrorException("error message");
+		}
+		if (args.length > 0 && "fail".equals(args[0])) {
+			throw new IllegalStateException("bad");
+		}
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader-classic/src/test/java/org/springframework/boot/loader/jarmode/LauncherJarModeTests.java

@@ -55,6 +55,7 @@ class LauncherJarModeTests {
 		System.setProperty("jarmode", "test");
 		new TestLauncher().launch(new String[] { "boot" });
 		assertThat(out).contains("running in test jar mode [boot]");
+		assertThat(System.getProperty(JarModeLauncher.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("0");
 	}
 
 	@Test
@@ -62,6 +63,25 @@ class LauncherJarModeTests {
 		System.setProperty("jarmode", "idontexist");
 		new TestLauncher().launch(new String[] { "boot" });
 		assertThat(out).contains("Unsupported jarmode 'idontexist'");
+		assertThat(System.getProperty(JarModeLauncher.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
+	}
+
+	@Test
+	void launchWhenJarModeRunFailsWithErrorExceptionPrintsSimpleMessage(CapturedOutput out) throws Exception {
+		System.setProperty("jarmode", "test");
+		new TestLauncher().launch(new String[] { "error" });
+		assertThat(out).contains("running in test jar mode [error]");
+		assertThat(out).contains("Error: error message");
+		assertThat(System.getProperty(JarModeLauncher.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
+	}
+
+	@Test
+	void launchWhenJarModeRunFailsWithErrorExceptionPrintsStackTrace(CapturedOutput out) throws Exception {
+		System.setProperty("jarmode", "test");
+		new TestLauncher().launch(new String[] { "fail" });
+		assertThat(out).contains("running in test jar mode [fail]");
+		assertThat(out).contains("java.lang.IllegalStateException: bad");
+		assertThat(System.getProperty(JarModeLauncher.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
 	}
 
 	private static final class TestLauncher extends Launcher {

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jarmode/JarMode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,7 +36,8 @@ public interface JarMode {
 	 * Run the jar in the given mode.
 	 * @param mode the mode to use
 	 * @param args any program arguments
+	 * @throws JarModeErrorException on an error that should print a simple error message
 	 */
-	void run(String mode, String[] args);
+	void run(String mode, String[] args) throws JarModeErrorException;
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jarmode/JarModeErrorException.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.loader.jarmode;
+
+/**
+ * Simple {@link RuntimeException} used to fail the jar mode with a simple printed error
+ * message.
+ *
+ * @author Phillip Webb
+ * @since 3.3.7
+ */
+public class JarModeErrorException extends RuntimeException {
+
+	public JarModeErrorException(String message) {
+		super(message);
+	}
+
+	public JarModeErrorException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/launch/JarModeRunner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.boot.loader.launch;
 import java.util.List;
 
 import org.springframework.boot.loader.jarmode.JarMode;
+import org.springframework.boot.loader.jarmode.JarModeErrorException;
 import org.springframework.core.io.support.SpringFactoriesLoader;
 import org.springframework.util.ClassUtils;
 
@@ -31,11 +32,31 @@ final class JarModeRunner {
 
 	static final String DISABLE_SYSTEM_EXIT = JarModeRunner.class.getName() + ".DISABLE_SYSTEM_EXIT";
 
+	static final String SUPPRESSED_SYSTEM_EXIT_CODE = JarModeRunner.class.getName() + ".SUPPRESSED_SYSTEM_EXIT_CODE";
+
 	private JarModeRunner() {
 	}
 
 	static void main(String[] args) {
 		String mode = System.getProperty("jarmode");
+		boolean disableSystemExit = Boolean.getBoolean(DISABLE_SYSTEM_EXIT);
+		try {
+			runJarMode(mode, args);
+			if (disableSystemExit) {
+				System.setProperty(SUPPRESSED_SYSTEM_EXIT_CODE, "0");
+			}
+		}
+		catch (Throwable ex) {
+			printError(ex);
+			if (disableSystemExit) {
+				System.setProperty(SUPPRESSED_SYSTEM_EXIT_CODE, "1");
+				return;
+			}
+			System.exit(1);
+		}
+	}
+
+	private static void runJarMode(String mode, String[] args) {
 		List<JarMode> candidates = SpringFactoriesLoader.loadFactories(JarMode.class,
 				ClassUtils.getDefaultClassLoader());
 		for (JarMode candidate : candidates) {
@@ -44,10 +65,17 @@ final class JarModeRunner {
 				return;
 			}
 		}
-		System.err.println("Unsupported jarmode '" + mode + "'");
-		if (!Boolean.getBoolean(DISABLE_SYSTEM_EXIT)) {
-			System.exit(1);
+		throw new JarModeErrorException("Unsupported jarmode '" + mode + "'");
+	}
+
+	private static void printError(Throwable ex) {
+		if (ex instanceof JarModeErrorException) {
+			String message = ex.getMessage();
+			System.err.println("Error: " + message);
+			System.err.println();
+			return;
 		}
+		ex.printStackTrace();
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jarmode/TestJarMode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,12 @@ class TestJarMode implements JarMode {
 	@Override
 	public void run(String mode, String[] args) {
 		System.out.println("running in " + mode + " jar mode " + Arrays.asList(args));
+		if (args.length > 0 && "error".equals(args[0])) {
+			throw new JarModeErrorException("error message");
+		}
+		if (args.length > 0 && "fail".equals(args[0])) {
+			throw new IllegalStateException("bad");
+		}
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/launch/LauncherTests.java

@@ -63,6 +63,7 @@ class LauncherTests {
 			System.setProperty("jarmode", "test");
 			new TestLauncher().launch(new String[] { "boot" });
 			assertThat(out).contains("running in test jar mode [boot]");
+			assertThat(System.getProperty(JarModeRunner.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("0");
 		}
 
 		@Test
@@ -70,6 +71,25 @@ class LauncherTests {
 			System.setProperty("jarmode", "idontexist");
 			new TestLauncher().launch(new String[] { "boot" });
 			assertThat(out).contains("Unsupported jarmode 'idontexist'");
+			assertThat(System.getProperty(JarModeRunner.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
+		}
+
+		@Test
+		void launchWhenJarModeRunFailsWithErrorExceptionPrintsSimpleMessage(CapturedOutput out) throws Exception {
+			System.setProperty("jarmode", "test");
+			new TestLauncher().launch(new String[] { "error" });
+			assertThat(out).contains("running in test jar mode [error]");
+			assertThat(out).contains("Error: error message");
+			assertThat(System.getProperty(JarModeRunner.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
+		}
+
+		@Test
+		void launchWhenJarModeRunFailsWithErrorExceptionPrintsStackTrace(CapturedOutput out) throws Exception {
+			System.setProperty("jarmode", "test");
+			new TestLauncher().launch(new String[] { "fail" });
+			assertThat(out).contains("running in test jar mode [fail]");
+			assertThat(out).contains("java.lang.IllegalStateException: bad");
+			assertThat(System.getProperty(JarModeRunner.SUPPRESSED_SYSTEM_EXIT_CODE)).isEqualTo("1");
 		}
 
 	}