What's wrong with this simple macro?

[dawkot]

    import macros
    
    macro procImplRepr(p: proc): string =
        p.symbol.getImpl.repr
    
    proc procA = discard
    proc procB(p: proc): string = p.procImplRepr
    
    echo procA.procImplRepr #returns proc procA = discard
    echo procB(procA) #returns nil
    

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