README's documented -Dexec.classpathScope=runtime fails for demos needing simple-xml (system-scoped dependency)

[sqlparser]

Summary

The root README documents one universal recipe for running any demo:

mvn -q exec:java -Dexec.mainClass=<package>.<Class> -Dexec.args="..." -Dexec.classpathScope=runtime

This fails with a NoClassDefFoundError for any demo that uses org.simpleframework.xml (e.g. dlineageBasic's Dlineage/DlineageRelation), because pom.xml declares that dependency with <scope>system</scope>, and Maven's runtime classpath scope does not include system-scoped dependencies — even though the jar is present at lib/simple-xml-2.7.1.jar.

Steps to reproduce

mvn package -DskipTests -q
cat > q.sql <<'SQL'
SELECT a.id, b.name FROM ta a JOIN tb b ON a.id = b.id WHERE a.x > 1;
SQL

mvn -q exec:java -Dexec.mainClass=demos.dlineageBasic.Dlineage \
    -Dexec.args="/f q.sql /t oracle" -Dexec.classpathScope=runtime

Actual output

[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.1.1:java (default-cli) on project gsp_demo_java:
An exception occurred while executing the Java class. org/simpleframework/xml/Serializer: org.simpleframework.xml.Serializer

Workaround (not documented anywhere)

Using -Dexec.classpathScope=compile instead of runtime (everything else identical) works and produces correct <columnImpactResult> XML output.

Root cause

pom.xml:

<dependency>
    <groupId>org.simpleframework</groupId>
    <artifactId>simple-xml</artifactId>
    <version>2.7.1</version>
    <scope>system</scope>
    <systemPath>${project.basedir}/lib/simple-xml-2.7.1.jar</systemPath>
</dependency>

system-scoped dependencies are excluded from Maven's runtime classpath by design; only compile/provided/system scope resolution paths include them directly, and exec:java's runtime classpathScope maps to the runtime classpath.

Suggested fix

Either change the README's universal recipe to use -Dexec.classpathScope=compile (since it appears to work for every demo tested, not just the ones needing simple-xml), or migrate simple-xml off system scope onto a normal Maven Central coordinate/local repo install so it participates in runtime scope correctly.

Environment

• OpenJDK 21.0.11, Apache Maven 3.8.7, Ubuntu 24.04.3

[sqlparser]

Fixed in ccd8be0: README and CI now document/use -Dexec.classpathScope=compile instead of runtime. compile scope includes the system-scoped dependencies (simple-xml, fastjson, etc.) that runtime scope excludes by design, so demos like dlineageBasic no longer hit NoClassDefFoundError.