bug#64735: 29.0.92; find invocations are ~15x slower because of ignores

[Dmitry Gutov]

On 20/07/2023 00:16, Spencer Baugh wrote:
> In Emacs alone, there are a few things we could do:
> - we could mitigate the find bug by optimizing the regexp before we pass
> it to find; this should basically remove all the overhead but makes the
> find command uglier and harder to edit
> - we could remove rare and likely irrelevant things from
> completion-ignored-extensions and vc-ignore-dir-regexp (which are used
> to build these lists of ignores)

I like these two approaches.

> - we could use our own recursive directory-tree walking implementation
> (directory-files-recursively), if we found a nice way to pipe its output
> directly to grep etc without going through Lisp.  (This could be nice
> for project-files, at least)

This will probably not work as well. Last I checked, Lisp-native file 
listing was simply slower than 'find'.