cannot print table-error

[Aliaksandr Rahalevich]

/app # resty-repl 
[1] lua(main)> x=function() error { a = 1 } end
=> nil
[2] lua(main)> x()
/usr/local/bin/lua: /usr/local/share/lua/5.1/resty/repl/formatter.lua:9: attempt to concatenate a table value
stack traceback:
	/usr/local/share/lua/5.1/resty/repl/formatter.lua:9: in function 'print'
	/usr/local/share/lua/5.1/resty/repl.lua:36: in function 'handle_input'
	/usr/local/share/lua/5.1/resty/repl.lua:51: in function 'start'
	...lib/luarocks/rocks/lua-resty-repl/0.0.6-0/bin/resty-repl:107: in main chunk
	[C]: at 0x55a1b3307a0e