$ jlink --module-path $JAVA_HOME/jmods:clojure-1.8.0.jar --add-modules clojure --output foo
Error: module-info.class not found for clojure module


When jlink debug property is turned on, we get this:


$ jlink --module-path $JAVA_HOME/jmods:clojure-1.8.0.jar --add-modules clojure -J-Djlink.debug=true --output foo
Plugin system-modules threw exception during transform
jdk.tools.jlink.plugin.PluginException: module-info.class not found for clojure module
at jdk.jlink/jdk.tools.jlink.internal.ModuleSorter.lambda$readModuleDescriptor$0(ModuleSorter.java:64)
at java.base/java.util.Optional.orElseThrow(Optional.java:385)
at jdk.jlink/jdk.tools.jlink.internal.ModuleSorter.readModuleDescriptor(ModuleSorter.java:62)
at jdk.jlink/jdk.tools.jlink.internal.ModuleSorter.addModule(ModuleSorter.java:72)
at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:591)
at jdk.jlink/jdk.tools.jlink.internal.ModuleSorter.<init>(ModuleSorter.java:57)
at jdk.jlink/jdk.tools.jlink.internal.plugins.SystemModulesPlugin.transform(SystemModulesPlugin.java:156)
at jdk.jlink/jdk.tools.jlink.internal.ImagePluginStack.visitResources(ImagePluginStack.java:274)
at jdk.jlink/jdk.tools.jlink.internal.ImageFileCreator.generateJImage(ImageFileCreator.java:182)
at jdk.jlink/jdk.tools.jlink.internal.ImageFileCreator.writeImage(ImageFileCreator.java:161)
at jdk.jlink/jdk.tools.jlink.internal.ImageFileCreator.create(ImageFileCreator.java:100)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask$ImageHelper.retrieve(JlinkTask.java:768)
at jdk.jlink/jdk.tools.jlink.internal.ImagePluginStack.operate(ImagePluginStack.java:206)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask.createImage(JlinkTask.java:398)
at jdk.jlink/jdk.tools.jlink.internal.JlinkTask.run(JlinkTask.java:263)
at jdk.jlink/jdk.tools.jlink.internal.Main.run(Main.java:54)
at jdk.jlink/jdk.tools.jlink.internal.Main.main(Main.java:33)

It seems that a plugin reports that an automatic module being used as root because of missing module-info.class resource! jlink should detect attempt to use automatic module as root upfront and report error clearly.