Invalid runtimes kept in runtime cache

[aahlenst]

#22 leaves partially extracted runtimes in the cache. For example, if the Linux archive fails to extract, I end up with the following contents in the runtime cache:

legal
release

As a result, jlinking can produce weird results. If I try to cross target Linux from a Windows JDK, jlink does not find the jmods in the Linux JDK and instead copies the Windows jmods. As a result, I end up with exe and dll files in a jlinked runtime for Linux. This behaviour by jlink is weird in itself, but nevertheless jlink.online should ensure that invalid runtimes do not end up in the cache.

[cilki]

Agreed. We could additionally ensure the jmods directory exists before passing it to jlink. As you noted, jlink uses the first module it finds, so that must always be the one from the target runtime.