A DESCRIPTION OF THE PROBLEM :
java throws a java.lang.module.InvalidModuleDescriptorException when a module-info.class in a directory in the module path exports a package that isn't under the same directory.

That is sensible behavior in many circumstances, but, in my case, I have the package under another directory which is patched into the module in question using --patch-module.

Given that I've patched into the module the directory that contains the exported package, I think that java should not throw the exception.

Example:
Module m is defined in classes/m/module-info.class, and it exports package p. module-info.class is the only child of directory classes/m.

Directory classes/patch contains p/Main.class.

Simplified command line:

java --module-path classes/m --patch-module m=classes/patch --module m/p.Main

The above will throw java.lang.module.InvalidModuleDescriptorException that says that "Package p not found in module". It would be nice if java realized p was patched into m via classes/patch, and didn't throw the error.

This would simplify supporting modules in Gradle Test tasks.