I get this error in latest patchlevel 289 of ruby 1.8.6

file: test.rb
x = 1
y = 2
z = x + y

rdebug test.rb

/usr/local/lib/ruby/gems/1.8/gems/ruby-debug-0.10.1/bin/rdebug:41:in 
`[]=': can't modify frozen string (TypeError)
	from 
/usr/local/lib/ruby/gems/1.8/gems/ruby-debug-0.10.1/bin/rdebug:41:in 
`debug_program'
	from /usr/local/lib/ruby/gems/1.8/gems/ruby-debug-0.10.1/bin/rdebug:330
	from /usr/local/bin/rdebug:19:in `load'
	from /usr/local/bin/rdebug:19

The problem does not occur in p251 and first appears in p252.

The problem appear with svn rev 17702.

For more info see ruby-debug rubyforge bug report here:

http://rubyforge.org/tracker/index.php?func=detail&aid=21276&group_id=1900&atid=7436

The problem also occurs using trunk 1_8.