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

[Stefan Monnier]

>> We could speed it up even further by byte-compiling this file, but this
>> has bumped into some corner cases problems so I'm sticking to
>> a non-compiled file for now.
> Which corner cases apply to this? If it is OK to ask you?

[ You quoted a lot of text, so I'm not completely sure, but `C-s` seemed
  to indicate that you were referring to just those above three lines
  I kept.  ]

I can't remember off-hand.  Actually, I have a vague recollection that
the problems turned out having some other origin.  So indeed we should
byte-compile the resulting file.

> compiling and baking package-quickstart.el into my init file (with
> disabled package-quickstart).

I don't know what this means.

> I have also optimized it slightly: every autoload file adds it's own
> path to load-path via add-to-list at startup time. But all those paths
> are known when package-quickstart-refresh runs, so we can simply
> concatenate them to one list and then emit code to just nconc emitted
> that list to load-path at startup (this is what I do in my init file).

I'm surprised a single call to `nconc` would be noticeably faster than
a hundred calls to `add-to-list`.  I mean, obviously it's a lot faster,
but unless you do that in a loop (which is not the case here),
I wouldn't expect the difference to be measurable.


        Stefan