Maven+JDK9 modules: Failed to parse module-info

Question

Using 9-ea+171, Maven 3.5.0

I am compiling a project with this module-info.java:

module org.project {
}

But it fails with a mysterious error:

[ERROR] Failed to parse module-info:
[ERROR] With qdox: null
(...)
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:testCompile (default-testCompile) on project rli-stubs: Execution default-testCompile of goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:testCompile failed: Failed to parse module-info -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:testCompile (default-testCompile) on project rli-stubs: Execution default-testCompile of goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:testCompile failed: Failed to parse module-info
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:213)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:309)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:194)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:107)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:993)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:345)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:191)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:563)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-testCompile of goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:testCompile failed: Failed to parse module-info
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:145)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
... 20 more
Caused by: java.lang.RuntimeException: Failed to parse module-info
at org.apache.maven.plugin.compiler.TestCompilerMojo.preparePaths(TestCompilerMojo.java:322)
at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:742)
at org.apache.maven.plugin.compiler.TestCompilerMojo.execute(TestCompilerMojo.java:170)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
... 21 more

I recreated the simplest form of the project here: https://github.com/benji/jdk9-mvn5-withqdoxnull

It seems to have something to do with src/test/java/ . If I remove that folder then the build passes.

Answer 1

You need to put module-info.java to src/main/java. Now it is located in src/main/java/com/test which is wrong. module-info.java must be a top level file.

Answer 2

You need maven-compiler-plugin at least 3.7.0 to use module system according to the table: https://cwiki.apache.org/confluence/display/MAVEN/Java+9+-+Jigsaw