type error on compilation

[increpare]

author David Skinner
homepage www.puzzlescript.net
verbose_logging
debug

========
OBJECTS
========

Background
lightgreen green
11111
01111
11101
11111
10111

Target
darkblue
.....
.000.
.0.0.
.000.
.....

Wall
brown darkbrown
00010
11111
01000
11111
00010

Player
black orange white blue
.000.
.111.
22222
.333.
.3.3.

Crate
orange
00000
0...0
0...0
0...0
00000

=======
LEGEND
=======

. = Background
# = Wall
P = Player
* = Crate
@ = Crate and Target
O = Target
player_Back = player and Background

=======
SOUNDS
=======

Crate move 36772507

================
COLLISIONLAYERS
================

Background
Target
Player
Wall, Crate

======
RULES
======

[ > Player | Crate ] -> [ > Player | > Crate ]
[ player_Back no Player | Player no Player ] -> [ | ]
[ player_Back no Player | Player no Player ] -> [ | ]

==============
WINCONDITIONS
==============

all Target on Crate

=======
LEVELS
=======

####..
#.O#..
#..###
#@P..#
#..*.#
#..###
####..

######
#....#
#.#P.#
#.*@.#
#.O@.#
#....#
######

cf #1163

Cannot read properties of undefined (reading 'lhs') TypeError: Cannot read properties of undefined (reading 'lhs') at rulesToMask (http://localhost:8000/src/js/compiler.js:1784:48) at loadFile (http://localhost:8000/src/js/compiler.js:3036:5) at compile (http://localhost:8000/src/js/compiler.js:3129:17) at HTMLAnchorElement.runClick (http://localhost:8000/src/js/toolbar.js:5:2)