It is annoying that the template doesn't resolve the symbol at template caller.

[Alogani]

Yes, it is a "known" difficulty that nesting templates won't always work, 
because the compiler might substitute one template before another. I generally 
rely on macro on those cases.

But the fact that the following example don't work worries me more :
    
    
    import strformat
    import macros
    
    macro t1(): untyped =
      return quote do:
        var i = 10
        echo fmt"i is {i}" # undeclared identifier: 'i'
    
    proc p1() =
      t1()
    
    when isMainModule:
      p1()
    
    
    Run