Re: Diffs between %s and %s end here

[Richard Stallman]

    Then we could use the same non-intrusive solution already implemented for
    compile: when compilation is successful it displays the successful status
    in the mode line of the compilation buffer in green.  When compilation
    fails, it displays the error code in the mode line in red.

Using faces that way seems like a good idea.  Still, the arguments
offered against inserting a "finished" message, like M-x compile
and M-x diff, seem to make much ado about very little.