Issue #4584 has been updated by Shota Fukumori. Status changed from Open to Rejected From http://redmine.ruby-lang.org/projects/ruby/wiki/HowToReport >If you'll report a bug in both Ruby 1.9 and Ruby 1.8: Ruby 1.9, and write like "this bug can reproduce at Ruby 1.8, too." So this issue (1.8) will be continued on Ruby1.9 tracker #4583. Closing. ---------------------------------------- Bug #4584: trace doesn't work for methods set up by attr_* http://redmine.ruby-lang.org/issues/4584 Author: Michael Klaus Status: Rejected Priority: Normal Assignee: Category: core Target version: ruby -v: ruby 1.8.7 (2011-02-18 patchlevel 334) [x86_64-linux] See also issue #4583 for Ruby 1.9. Methods set up with attr_accessor or alike are not traceable: class Foo attr_writer :bar def baz=(value) @baz = value end end set_trace_func proc{|*args| puts args.inspect} @foo = Foo.new # will be traced @foo.bar = 'bar' # call to bar= will not be traced @foo.baz = 'baz' # call to baz= will be traced Expected behavior: "c-call" and "c-return" are traced. -- http://redmine.ruby-lang.org