IMHO it should be possible at the debugger prompt to manually eval a line with use re 'debug' enabled,

This could be automatized with an alias command to be manually invoked, to take the next (or last) line to be executed to be debugged.

My quick testing couldn't make it work, either because

• my Perl version is too old for use re 'debug'
• because re-debugging needs to be enabled at start time and than disabled
• probably both

Left as an exercise to interested monks with much time... :)