[BUG] Misleading error message in 'unit' declarations

[apache2]

This error messag makes sense to me, it's saying that units must be defined 
with constant ints:
#!!# var x = 4096; unit PAGE_SIZE = x;
<stdin>:1:32: error: expected constant integral value for unit
var x = 4096; unit PAGE_SIZE = x;;
                               ^
I think it should say the same when trying to define a 'unit' from an offset 
(because casting to integral would still not work, since it needs to be 
constant):
#!!# var x = 4096#B; unit PAGE_SIZE = x;
<stdin>:1:34: error: invalid cast to integral
var x = 4096#B; unit PAGE_SIZE = x;;
                                 ^