Thank you for your report.

  In mail "Re: FileUtils bug and fix"
    Chad Fowler <chad / chadfowler.com> wrote:

> # Alternatively same src/dest could be checked for in fu_each_dest_src, so
> # that mv() and ln() also benefit?
> # 
> 
> Good point.  I hadn't taken the time to really look around and see that 
> other methods could use the same thing.

I should modify fu_each_src_dest, except ln_s.
cp("a", "a"), mv("a", "a"), ln("a", "a"), install("a", "a")
should raise error.


> Is there concensus that this is undesired behavior?  Everyone I've talked 
> to so far has agreed.  

I think so.  "cp a a" causes error on UNIX sh,
FileUtils also should raise error.


Best Regards,
Minero Aoki