bizarre name clash with template

[jibal]

This code produces the very surprising message
    
    
    x.nim(9, 1) template/generic instantiation of `t` from here
    x.nim(7, 9) Error: undeclared identifier: 'x'
    
    The error is for bod(x)
    If I change the for loop variable to anything other than x, it works.
    
    If this is indeed a bug, what title should I file it under?
    
    .. code-block:: nim
      template t(body: untyped) =
        proc bod(a: int) =
          let x {.inject.} = a
          body
        
        for x in [1]:
          bod(x)
      
      t:
        echo x