Issue1550

Jython POSIX won't work when JRuby 1.4 is in the classpath:

java.lang.NoSuchFieldError: LoadNow

The specific conflict seems to be over jnr-posix.jar.

OK, figured it out. Add this to the build.xml jar-complete task:

<rule pattern="jni.**" result="org.python.jni.@1"/>

Can any of the committers do this?

On second look, my solution is not working, because jarjar cannot deal with packages which have a "-" in them.

I've opened a bug in jarjar about it. Any other ideas how to rename these classes for the complete jar?

Third look. ;)

I built a patched version of jarjar that does support dashes in package names, and used it to build Jython. Still no good -- it seems that the JNI specific stuff is hardcoded in jnr-posix.jar.

The solution for me, for now, is to ship Prudence with Subversion builds of both Jython and JRuby, since they use compatible JFFI libs.

But I think it's still important to find a way to fix Jython so that it plays nicely with others.

From IRC:

17:43  wmeissner> sabi: yes - the problem is that the jaffl.jar and
                  jnr-posix.jar in jython are more recent than the ones in jruby
17:43  wmeissner> well, in jruby-1.4 anyway
17:43  sabi> sure, but the idea would be that jython could use jarjar to
             maintain its own copy of jaffl/jnr-posix so it doesn't conflict
17:43  sabi> is there any reason that couldn't happen?
17:44  sabi> or would the native bits conflict?
17:44 * sabi really doesn't know too much about how these things work
17:44  wmeissner> the native bits should be ok ... jaffl might be tricky, it
                  loads its provider via reflection, so that might break
17:45  wmeissner> and unfortunately, you can't jarjar rename jffi at all, since
                  it has jni methods
17:46  sabi> yargh. ok.
17:46  sabi> is jffi at least relatively stable? :)
17:46  wmeissner> I'm really not sure why renaming all the stuff in /jni makes 
                  any difference to that bug
17:46  sabi> i think it's causing jython to not be able to find jni any more
17:47  wmeissner> jffi should have a version 1.0 out soon
17:47  sabi> er jffi or whatever
17:47  sabi> so it probably never even tries to load it
17:47  wmeissner> and given that 0.6 has been stable for 6 months or so, I'd 
                  say it should be ok for another 6 ... or 12 .. or more 
                  hopefully
17:47  sabi> ok. so hopefully the next time jruby and jython release, 
             everything should be good
17:48  wmeissner> yes.  I'm trying to round up people to compile the stubs on 
                  $favourite_platform

So hopefully this will be resolved before we release 2.5.2.  Sorry about the inconvenience.

17:49  wmeissner> technically he could also fix the problem by rebuilding 
                  jruby-1.4 with the latest jaffl.jar
17:50  wmeissner> jaffl is pure-java, and relatively api-backward-compatible
17:50  wmeissner> and is where the jnr-posix problem is from

Thanks, guys. For now Prudence will ship with svn snapshots of both projects, for greater glory.

Speaking of which, JRuby 1.4 gave me considerable grief in its JSR-223 support. But that's a story for another night.