Unexpected package bug in jdk-9-ea+109

[Paul Benedict]

File src/z/module-info.java:
package z;

Command line:
javac -d out src/z/module-info.java

Output:
An exception has occurred in the compiler (9-ea). Please file a bug against
the Java compiler via the Java bug reporting page (http://bugreport.java.com)
after checking the Bug Database (http://bugs.j
ava.com) for duplicates. Include your program and the following diagnostic
in your report. Thank you.
java.lang.NullPointerException
        at
com.sun.tools.javac.comp.TypeEnter$ImportsPhase.checkClassPackageClash(jdk.compiler at 9-ea
/TypeEnter.java:362)
        at
com.sun.tools.javac.comp.TypeEnter$ImportsPhase.resolveImports(jdk.compiler at 9-ea
/TypeEnter.java:342)
        at
com.sun.tools.javac.comp.TypeEnter$ImportsPhase.access$1600(jdk.compiler at 9-ea
/TypeEnter.java:284)
        at
com.sun.tools.javac.comp.TypeEnter.lambda$ensureImportsChecked$0(jdk.compiler at 9-ea
/TypeEnter.java:169)
        at
com.sun.tools.javac.comp.TypeEnter.finishImports(jdk.compiler at 9-ea
/TypeEnter.java:220)
        at
com.sun.tools.javac.comp.TypeEnter.ensureImportsChecked(jdk.compiler at 9-ea
/TypeEnter.java:169)
        at com.sun.tools.javac.comp.Enter.complete(jdk.compiler at 9-ea
/Enter.java:553)
        at com.sun.tools.javac.comp.Enter.main(jdk.compiler at 9-ea
/Enter.java:524)
        at
com.sun.tools.javac.main.JavaCompiler.enterTrees(jdk.compiler at 9-ea
/JavaCompiler.java:1038)
        at com.sun.tools.javac.main.JavaCompiler.compile(jdk.compiler at 9-ea
/JavaCompiler.java:904)
        at com.sun.tools.javac.main.Main.compile(jdk.compiler at 9-ea
/Main.java:261)
        at com.sun.tools.javac.main.Main.compile(jdk.compiler at 9-ea
/Main.java:143)
        at com.sun.tools.javac.Main.compile(jdk.compiler at 9-ea/Main.java:55)
        at com.sun.tools.javac.Main.main(jdk.compiler at 9-ea/Main.java:41)

Cheers,
Paul