I am glad that somebody managed to repeat the error. I think that people were beginning to think I was seeing things :-)

I want to try some more tests myself but, to answer your questions:

The variable name $re_bad is meant to imply that Perl is doing something bad with a valid regex. The regex is meaningless, that was just as small as I could get it. (As mentioned above, if I remove any further elements, I do not get the error.) The real regex is much longer. In fact, I got this error for a couple of regexes - one to match a SQL label and one to match a SQL global variable.

Yes, I intentionally used single quote delimeters. I have also observed the behaviour when using other delimeters. However, so far, I only get the problem when using /x...

Kevin