What's wonderful about this bug is that giving the troll to itself to eat gets rid of the troll, but doesn't clear the TROLL-FLAG. ;( So then when you try to exit the room to the NORTH, EAST or SOUTH, you get TCHOMPed, and the non-existent troll fends you off with a menacing gesture! ;) So you are truly fucked, and can't finish the game.

>EAST

The troll fends you off with a menacing gesture.

    #ROOM {"MTROL"

    "You are in a small room with passages off in all directions. 
    Bloodstains and deep scratches (perhaps made by an axe) mar the
    walls."
           "The Troll Room"
           %<> #EXIT {"WEST" "CELLA"
              "EAST" #CEXIT {"TROLL-FLAG" "CRAW4" %,TCHOMP}
              "NORTH" #CEXIT {"TROLL-FLAG" "PASS1" %,TCHOMP}
              "SOUTH" #CEXIT {"TROLL-FLAG" "MAZE1" %,TCHOMP}}
           (#FIND-OBJ {"TROLL"})}

    <PSETG TCHOMP "The troll fends you off with a menacing gesture.">