bug#41646: Startup in Windows is very slow when load-path contains many

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

>> We can easily detect changes to `load-path` itself, of course, but as
>> for changes to the content of the directories in `load-path` that would
>> be more difficult&costly, admittedly.  My plan was to do nothing
>> about it (i.e. allow the cache to go stale): if we use the cache only to
>> tell `load` in which directory to look for the file, it should usually
>> be safe because IME it's rare for files to be added/removed from
>> directories such that it changes from which directory a given ELisp file
>> is loaded.  But of course we could also make efforts to try and keep our
>> cache consistent, e.g. via OS-level notification infrastructure or
>> by flushing the cache after a N seconds.
> Agree the changes are difficult and costly.

I don't understand: I didn't say (nor do I think) that any of that is
complex or costly.


        Stefan