CoffeeScript indentation problem errors are very bad

[nwinter]

fun = ->
    a = 'a'
        b = 'b'

Syntax error on line 5, column 14: unexpected '=' (\u003D)
2 : 
3 :     fun = ->
4 :         a = 'a'
5 :             b = 'b'
^ :             ^
6 :