Re: Compile Mode and "host" Emacs

[Stephen J. Turnbull]

Jorgen Schaefer writes:

 > From within that Emacs, I then run programs such as ert-testrunner
 > which use Emacs to run automated tests.

Nope, not the same use-case.

(defmacro with-emacs-exe-set-in-environment (pollute-permanently &rest body)
  "Documentation is an exercise for the reader.

Making the unset work safely (handling previous settings and signals
in BODY) and beautifully also left as an exercise."

  (setenv EMACS_EXE_VARIABLE_YOU_LIKE_BEST
          (expand-file-name invocation-name invocation-directory))
  ,@body
  (unless pollute-permanently
    (setenv EMACS_EXE_VARIABLE_YOU_LIKE_BEST nil t)))

is all you (and ert-testrunner) need, FVO "you" which are singular
(eg, "I", see quoted text above).  You could also generalize the macro
to take a string which is the full name of the executable to use.

The OP's problem is organizational, but the site-start.el method I
proposed should handle that.