[R] dput(..., file = stderr())

[Benjamin Tyner]

Curious to know if this warning is expected behavior, and if so, what is 
the recommended way instead:

     > dput(letters, file = stderr())
    c("a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l",
    "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y",
    "z")
    Warning message:
    In dput(letters, file = stderr()) : wrote too few characters

(I ask because it doesn't happen when using file = stdout())