FYI, I have encountered the following bug with ruby_debug breakpoints:
A breakpoint will break in any file being executed for which the current
line number matches the breakpoint line number and the breakpoint
filename is a suffix of the filename of the file being executed.
Thus, e.g., if a breakpoint is set for “server”, the breakpoint will
incorrectly break if the designated line number is encountered in
“httpserver”.
I have submitted a bug report to the project at RubyForge with a
suggested fix.
-Todd