bug#74382: `compile-first` Make rule is no longer using `load-prefer-newer`

[Konstantin Kharlamov]

On Sun, 2024-11-17 at 08:25 +0100, Gerd Möllmann wrote:
> Konstantin Kharlamov <Hi-Angel@yandex.ru> writes:
> 
> > Sure, I just reproduced it after removing all `.elc` files in the
> > repo,
> > here how:
> > 
> > 1. `git checkout f2f13fa630b` (a commit from April)
> > 2. `make -j$(nproc)` to compile. Note: you don't need to wait for
> > build
> > to finish, I just waited for all files under `lisp/emacs-lisp`
> > directory to finish compilation, and then ^C'ed it.
> > 3. `git checkout 29098a291f5` (a November commit).
> > 4. `make -j$(nproc)`
> 
> This would always work if lisp/Makefile would rm the .elc files from
> COMPILE_FIRST, right? I suspect this isn't done to speed up the build
> in
> the usual case, and because it's a bit difficult to automatically
> determine if it has to done or not.
> 
> Does a "make clean" after the checkout in (3) make it work?

I don't think so, because `make clean` for some reason doesn't remove
`.elc` artifacts.