The search string seems to be erroneously evaluated in V6.0 but not V5.7. In one of the error logs below, I searched for "option add" and in the other I searched for "$g". In the case of a space, putting quotes around the search string will succeed, but for the dollar sign, curly braces are necessary.
Filing bug while I still have the log files.
Ya know, I'd swear this was fixed once before. And its odd if it does really work for V5.7; maybe I'll look to see if anything appears changed between the two releases. In any event, standby...
OK - understand what happened - extra reparsing from EVAL caused unprotected search term to look like TCL and it all went south. V5.7 did not use "eval", which was added trying to simplify the command. Will repair.
Fix scheduled for eventual new version; can refer to commit 225 if details desired in the interim