Added Sokolov Yura‘s performance patches for 1.9.3 Added Narihiro Nakamura’s Lazy Sweep garbage collector (backported by Sakolov Yura) Why isn't this work a part of an official ruby release? Patched Ruby 1.9.3 to export the right symbols to work with ruby-debug Built Ruby 1.9.3 with Google’s high performance memory alloactor, tcmalloc Why aren't Debian and Ubuntu doing this already?
imo, I don't think Debian and Ubuntu should do this - it's not really their job. Distros should, for the most part, just be packaging upstream code and not maintaining an unofficial fork. Though counter to this, RedHat basically maintain their own fork of the Linux kernel but it's a bit of a special case, and they do employ full time kernel developers to do it!
If a ruby release didn't have a working debugger but this could be easily patched, then I would expect distros to do that. However, I'm not familiar enough with the ruby ecosystem to know the context of "patched Ruby 1.9.3 to export the right symbols to work with ruby-debug"