Processing locked up on regexp

[toots]

The following creates a process lock:

let rex = Re.Pcre.regexp "^ *";;
Re.Pcre.substitute ~rex ~subst:(fun _ -> "") "Condition which should be satisfied.";;

I understand that the * should most likely be escaped but:

• Other implementations accept this regexp as valid. Similar issue as in Parse error #200
• The library should obviously not stall