Your example doesn't work. The re pragma (as far as I can tell) does something when the regexp is created, so if I run your code, nothing is output.

However, even if it was, this really doesn't do what I want. Imagine the following code:

$re1 = qr/.../;
$re2 = qr/.../;
...
$reN = qr/.../;

@str = ('some','list','of','strings');

foreach my $str (@str) {
   $str =~ /$re1/;
   $str =~ /$re2/;
   ...
   $str =~ /$reN/;
}
[download]

That's basically the situation that I have. But I don't want to turn on debugging for all regexps, or even for a single regexp every time it is used. What I want is to be able to debug $re2 when applied to the 5th string and nothing else.

The way I want this to work is that I run this program in the debugger, step through until I get to the particular regexp match that I want to debug, and then I type "use re 'debug'" and I'm ready to go.

Unfortunately, it doesn't work. The regexp was already created without debugging turned on, so (as far as I can tell), there is no way to turn it on for this one particular match.

Anyway, as I said, it's far from the end of the world... I can turn on debugging and then run the script to the point i'm interested in and ignore all the unwanted debug output from all the other times the regexp was matched. This is mainly a convenience question.