Hello, After some hunting through the IronRuby code (I wrote a little test app which causes rbx to throw a SyntaxErrorException), I figured out that the parser has a problem parsing a certain sequence of tokens which appears to be valid ruby code (given that it runs fine in my MRI). I''ve attached a .patch file as per John''s "submitting a patch" video - which contains a test showing the problem, which appears in statements of the form: a = b == something or return nil which fails with "syntax error, unexpected kRETURN". Unfortunately, I don''t have the faintest clue about where to go in the code to fix this error, so I''ll leave that part to someone more capable for now. I discovered the bug while trying to require ''net/http'' in a test program after copying net/http from my MRI to somewhere rbx could find it. Presently, this file cannot be successfully parsed - it fails around line 1152 in def [](key) on a statement similar to the one I wrote above. Unfortunately, my country''s monopolistic telecommunications provider apparently runs a transparent proxy which makes it impossible for me to log into rubyforge and load this as a bug myself (see http://rubyforge.org/tracker/index.php?func=detail&aid=10650&group_id=5&atid=101for details), so I''ll resort to posting bugs here until this issue is resolved. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://rubyforge.org/pipermail/ironruby-core/attachments/20070916/76f9fa74/attachment.html -------------- next part -------------- A non-text attachment was scrubbed... Name: assign_or_return_bug_test.patch Type: application/octet-stream Size: 793 bytes Desc: not available Url : http://rubyforge.org/pipermail/ironruby-core/attachments/20070916/76f9fa74/attachment.obj