Use the same FileSystem as the outputDir.

[JakeWharton]

Otherwise java.nio.file.ProviderMismatchException can be thrown if it differs from FileSystems.getDefault() (which was implicitly used by Paths.get()).

[JakeWharton]

Actually it looks like there's other path assumption problems in Retrolambda.java as well.

[luontola]

In what situation would this result in Retrolambda not working? I'd like to reproduce it.

[JakeWharton]

I was loading class files directly from a pre-existing jar by using FileSystem.newFileSystem to mount it as a zip.

[JakeWharton]

I'll note that this is not a comprehensive fix as I gave up and just extracted the jar.

[luontola]

How were you invoking Retrolambda? AFAIK, it shouldn't be possible to pass in a custom file system even in you call net.orfjackal.retrolambda.Retrolambda#run programmatically.

[JakeWharton]

Nothing is final or hidden so I just subclassed Config and return what I want. Ideally there would be a nice API on which the CLI was built for programmatic use. I'm scripting a conversion of Java 8 libraries to Java 6 in our tooling so that updates of those libraries are easy.

[luontola]

OK. Such an API could also be used for implementing #44.

[luontola]

This is included in Retrolambda 2.1.0.