Issue #8366 has been reported by anuraguniyal (anurag uniyal). ---------------------------------------- Bug #8366: Exception.message take time to execute depending on the instance variables https://bugs.ruby-lang.org/issues/8366 Author: anuraguniyal (anurag uniyal) Status: Open Priority: High Assignee: Category: Target version: ruby -v: ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.4.2] Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN I am seeing very interesting and catastrophic behavior with ruby, see the code below class ExceptionTest def test @result = [0]*500000 begin no_such_method rescue Exception => ex puts "before #{ex.class}" st = Time.now ex.message puts "after #{Time.now-st} #{ex.message}" end end end ExceptionTest.new.test Ideally ex.message should not take any time to execute and hence Time taken should be in ms, but here is the output ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.4.2] before NameError after 0.462443 undefined local variable or method `no_such_method' for #<ExceptionTest:0x007fc74a84e4f0> If I assign `[0]*500000` to a local variable instead of instance variable e.g. `result = [0]*500000` it runs as expected ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.4.2] before NameError after 2.8e-05 undefined local variable or method `no_such_method' for #<ExceptionTest:0x007ff59204e518> **It looks like somehow `ex.message` is looping thru the instance variables, why it would do so, please enlighten me!** I have tried it on ruby ruby-1.9.2-p290, ruby-1.9.1-p376 and whatever version the ruby on codepad.org is. -- http://bugs.ruby-lang.org/