make bootstrap required today; mechanism for this?

[Chad Brown]

Updating today, with `make all install' (macosx, --with-ns), I got:

  Compiling /Users/chadp/Project/emacs/working/lisp/gnus/mml.el
  Source file `/Users/chadp/Project/emacs/working/lisp/gnus/rfc2047.el' newer 
than byte-compiled file

  In toplevel form:
  gnus/mml.el:34:1:Error: Symbol's value as variable is void: password-cache

A subsequent `make bootstrap' resolved the problem, so it's not a showstopper, 
but I recall dimly someone mentioning a `depend' target that would allow my 
build-script to avoid this problem in the future -- did that ever happen, or am 
I remembering a suggestion/idea as an implementation?

*Chad