diff --git a/main-runner/pom.xml b/main-runner/pom.xml
index b002316..083f495 100644
--- a/main-runner/pom.xml
+++ b/main-runner/pom.xml
@@ -15,6 +15,8 @@
 
 		<hello.agent.opt>-javaagent:${io.foldright.study:hello-agent:jar}</hello.agent.opt>
 		<world.agent.opt>-javaagent:${io.foldright.study:world-agent:jar}</world.agent.opt>
+		<!-- dummy default value, overridden by profile -->
+		<main.run.debug.java.opt>-ea</main.run.debug.java.opt>
 	</properties>
 
 	<dependencies>
@@ -45,6 +47,8 @@
 						<argument>-Duser.language=en</argument>
 						<argument>-Duser.country=US</argument>
 
+						<argument>${main.run.debug.java.opt}</argument>
+
 						<argument>-classpath</argument>
 						<classpath/>
 
@@ -56,6 +60,17 @@
 	</build>
 
 	<profiles>
+		<profile>
+			<id>java-main-run-enable-debug</id>
+			<activation>
+				<property>
+					<name>env.STUDY_MAIN_RUN_DEBUG</name>
+				</property>
+			</activation>
+			<properties>
+				<main.run.debug.java.opt>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</main.run.debug.java.opt>
+			</properties>
+		</profile>
 		<!-- agent config mode profiles -->
 		<profile>
 			<id>enable-hello-and-world-agents-mode</id>
@@ -84,9 +99,7 @@
 								<argument>-Duser.language=en</argument>
 								<argument>-Duser.country=US</argument>
 
-								<!--
-								<argument>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</argument>
-								-->
+								<argument>${main.run.debug.java.opt}</argument>
 
 								<argument>${hello.agent.opt}</argument>
 								<argument>${world.agent.opt}</argument>
@@ -128,9 +141,7 @@
 								<argument>-Duser.language=en</argument>
 								<argument>-Duser.country=US</argument>
 
-								<!--
-								<argument>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</argument>
-								-->
+								<argument>${main.run.debug.java.opt}</argument>
 
 								<argument>${hello.agent.opt}</argument>
 
@@ -171,9 +182,7 @@
 								<argument>-Duser.language=en</argument>
 								<argument>-Duser.country=US</argument>
 
-								<!--
-								<argument>-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005</argument>
-								-->
+								<argument>${main.run.debug.java.opt}</argument>
 
 								<argument>${hello.agent.opt}</argument>
 								<argument>${hello.agent.opt}</argument>