assembly <files> uses maven parent relative path and not the modules relative path

In mvn 2.0.4 if I have an assemly descriptor that has the following:

<files>
<file>
<source>src/site/apt/index.apt</source>
<outputDirectory></outputDirectory>
<destName>README.txt</destName>
</file>
</files>

and a maven project that looks like:

Maven Assembly Bug

• pom.xml
• assembly-bug-module
• pom.xml
• src/site/apt/index.apt

with the assembly:assembly bound to the package phase inside assembly-bug-module/pom.xml as
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<id>package-assembly</id>
<phase>package</phase>
<goals>
<goal>assembly</goal>
</goals>
<configuration>
<descriptors>
<descriptor>
src/main/assembly/bin.xml
</descriptor>
</descriptors>
</configuration>
</execution>
</executions>
</plugin>

then when I run mvn install inside assembly-bug-module:
assembly-bug-module> mvn install
the command works fine

When I run mvn install inside the "Maven Assembly Bug" directory the command will fail
Maven Assembly Bug> mvn install

[INFO] [assembly:assembly

{execution: package-assembly}

]
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error adding file to archive: <path>\Maven Assembly Bug\src\site\apt\index.apt isn't a file.

Example project is attached as a zip file.

Trying to change the descriptor to use ${project.build.sourceDirectory} does not work as this is not resoolved.

[INFO] Error adding file to archive: <path>\Maven Assembly Bug\assembly-bug-module\${project.build.sourceDirectory}
\site\apt\index.apt isn't a file.