Hi, As promised, I''m trying to track down and reproduce various bugs I have hit. The first one I have is that my code is calling caller(0)[1] which expects the path to the calling method. However, if i''m using running the ir, then it can''t find the file or the method name, and the line number is 0 in the stack trace, as such the information being returned is incorrect which is causing expand_path to blow up. Hope that makes sense? E:\IronRuby\r156\build\debug>ir expandpath_call.rb :0 E:\IronRuby\r156\build\debug>ir -D expandpath_call.rb expandpath_call.rb:4 E:\IronRuby\r156\build\debug>ruby expandpath_call.rb expandpath_call.rb:4 File: expandpath_call.rb require ''expandpath.rb'' $a = A.new $a.method File: expandpath.rb class A def method puts caller(0)[1] end end In the actual code, the stack frame looks something like this: {#top-level-method#$18##18 at offset 10911 in file:line:column <filename unknown>:0:0} Hope this helps Cheers Ben -------------- next part -------------- A non-text attachment was scrubbed... Name: expandpath.rb Type: application/octet-stream Size: 108 bytes Desc: not available URL: <http://rubyforge.org/pipermail/ironruby-core/attachments/20081006/c805df34/attachment.obj> -------------- next part -------------- A non-text attachment was scrubbed... Name: expandpath_call.rb Type: application/octet-stream Size: 48 bytes Desc: not available URL: <http://rubyforge.org/pipermail/ironruby-core/attachments/20081006/c805df34/attachment-0001.obj>