Message12604

It's easy to reproduce (sort of). In an installed Jython, all you have to do is:

PS 272a1> jython -c "from org.python.util import JycompileAntTask"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
java.lang.NoClassDefFoundError: org/python/apache/tools/ant/taskdefs/MatchingTask

It is apparently as easy to reproduce in the dev environment:

PS jython-trunk> dist\bin\jython -c "from org.python.util import JycompileAntTask"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
java.lang.NoClassDefFoundError: org/apache/tools/ant/taskdefs/MatchingTask

but this is a false positive (look carefully at the binary name of the missing class). This is simply a consequence of not having an ant.jar on the path, and on my machine I can quiet it by setting a CLASSPATH:
PS jython-trunk> $env:CLASSPATH="dist\jython-dev.jar;dist\javalib\*;C:\Program Files\ant\lib\ant.jar;."
PS jython-trunk> dist\bin\jython -c "from org.python.util import JycompileAntTask"

but this trick doesn't work in the installed environment.

So it's easy to reproduce (though tedious as making and running the installer).

I've noticed a few times the scope there is to introduce errors after the last test and before Jython reaches users. The regression tests in the dev environment cover a lot conveniently, but don't run on the delivered Jython cleanly (for reasons I believe I understand).