Using plain old classpath with Maven and Surefire

Because of the particular nature of our product, I have some big restrictions on class loading. Specifically, since I have my own specialized system class loader, the surefire isolated class loader is a non-starter.

Diagnosing the following problem took way too long: the documented useManifestOnlyJar property of the surefire plugin does not work in surefire 2.4.2, which is what my install of Maven2 picked up by by default.

Since there are some potentially confusing interaction between surefire configuration properties, I include here the entire block you will need in your pom.xml to use "plain old Java class paths":

<build>
  <plugins>
  ...
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-surefire-plugin</artifactId>
      <version>2.4.3</version>
      <configuration>
        <forkMode>once</forkMode>
        <useManifestOnlyJar>false</useManifestOnlyJar>
        <useSystemClassLoader>true</useSystemClassLoader>
      </configuration>
    </plugin>
  ...
  </plugins>
<build>

In this case, I ran maven with maximal verbosity (mvn -X test [yadda yadda]) and eventually noticed:

[DEBUG]   (f) useSystemClassLoader = true

...but no line talking about useManifestOnlyJar. Did I spell it wrong? Is it not recognized? Is it a surefire bug? (yes.)

Now that I have the classpath working, the next step is to figure out why useSystemClassLoader is being ignored. What?

System.out.println("CL: " + this.getClass().getClassLoader().toString());

says:

Running com.kabira.iotest.AddressTest
CL: org.apache.maven.surefire.booter.IsolatedClassLoader@7051630a

Sigh.

Documentation for surefire plugin is here.