Re: setenv

[Richard Stallman]

    > I don't think that would be needed, because environ is not used except for
    > initializing process-environment and for fiddling with the time zone.

    It is used for a few other things, such as looking for executable files 
    along PATH.

Emacs checks PATH at the very beginning, to set up exec-path.
But once Emacs is running, it does not use PATH any more;
you need to set exec-path, not change the environment.