Re: "reference to free variable" only during initialization

[Noam Postavsky <npostavs@users.sourceforge.net>]

On Sat, Feb 18, 2017 at 6:01 PM, Yuri D'Elia <wavexx@thregr.org> wrote:
> with ~/.emacs.d/lisp containing modeline-posn.el from melpa. There's no
> other file. I indeed had to add (package-initialize) to reproduce the
> issue, but I'm not sure why it has some influence. Maybe just some
> delay.
>
> Right off the bat, could you reproduce it with this?

Yes, the reason package-initialize matters is just that it loads
bytecomp and advice.el only decides to compile if that has been
loaded:

    (defun ad-should-compile (function compile)
      (cond
       ...
       ;; everything else means `maybe':
       (t (featurep 'byte-compile))))

(bytecomp.el provides both `bytecomp' and `byte-compile').

>
> Evaling after-init-time makes no difference,

--eval '(setq after-init-time t)' has no effect, but doing

    (let ((after-init-time t))
      (require 'modeline-posn))

in the init.el file does prevent the warning from popping up. It also
improves the error message: the prefix becomes
".emacs.d/lisp/modeline-posn.el:Warning:" instead of "Warning
(bytecomp):". This is because byte compilation is let-binding
warning-prefix-function which is not saved for delayed warnings.