EnvironmentVariableTests depends on format of string representation of objects. While working on Jython 2.7 the test failed due to: AssertionError: "[u'ignore::DeprecationWarning']" != "['ignore::DeprecationWarning']" Attached is a patch to get the output of child process via marshal and also use set so order is not important.
Jython's sys.warnoptions should probably just contain strs instead of unicode. Otherwise I suspect unicode values could break the warnings module's usage of it