Re: bug#30854: 27.0.50; Speeding up package.el startup

[Stefan Monnier]

>> Set `package-load-list`.
> Is it up to user to serialize this list to disk for next session or
> is it somehow done on the user behalf?

It's assumed it's manually set in the user's init file or via Custom, yes.

For example, I locally disable AUCTeX as follows:

    (setq package-load-list '((auctex nil) all))

> If user disabled a package, and generated new autoloads, and then
> there were new packages installed in site repository, how would Emacs
> know which are disabled and which are just new ones?

If `package-load-list` says it's disabled, then it's disabled, and if
not, then it's not.  I guess I don't understand the question.

> 1. is probably trivial, since package.el already can do that.  It
> just needs to call package-quickstart-refresh from few more places.

Right.

> 2. as well

Indeed.

> 3. will need some extra code, mostly or only in startup.el

It also needs extra code in `package.el` when creating
`package-quickstart.el` to record the mtimes.

BTW, other cases where the `package-quickstart.el` needs to be recreated
is when the user changes `package-load-list` or
`package-directory-list`, so we may also want to remember the values of
those vars when creating the `package-quickstart.el`.  But this part is
more tricky: it can be perfectly normal for the users to set those vars
in their init file, i.e. after `package-quickstart.el` is loaded (it's
actually one of the benefits of using `package-quickstart.el`: you don't
need to set `package.el`'s vars in your `early-init.el`), so we should
not check those vars for freshness before loading
`package-quickstart.el` but rather later.

> 4. will need some extra code in package.el, maybe in startup.el too, not sure

AFAIK there's nothing to be done for 4.


        Stefan