[1.9/12928] problem with -r debug

[Ollivier Robert]

Hello,

I'm running 1.9 from svn (revision 12928) on OS X. I appreciate that
the hooks for the debugger have been put in place but trying to run a
program in it leads to this as soon as I hit "s" on some lines:

321 [9:40] roberto@roberto-al:HG/raw-scripts> /usr/local/bin/ruby -r
debug find-photos.rb ~/Documents
Debug.rb
Emacs support available.

find-photos.rb:20:$KCODE = "u"
(rdb:1) b main
Set breakpoint 1 at find-photos.rb:main
(rdb:1) c
0: ArgumentError

or

find-photos.rb:181: def keys
(rdb:1)
s
find-photos.rb:187: def [](base_name)
(rdb:1)
s
find-photos.rb:195:def main(argv)
(rdb:1)
s
find-photos.rb:216:if $0 == __FILE__ then
(rdb:1)
s
find-photos.rb:217: exit(main(ARGV) || 1)
(rdb:1)
s
0: ArgumentError

code fragment is

...
if $0 == __FILE__ then
exit(main(ARGV) || 1)
end

Any idea?