bug#20887: 'make bootstrap' now verrrry slow due to recent isearch changes

[Glenn Morris]

Paul Eggert wrote:

> That's just the beginning.  The real slowness comes later in the
> build.  Each time it's compiling something else, Emacs has to reload
> isearch.el (as isearch.elc doesn't exist yet), and this takes many
> minutes.  And it does this over and over. 

That means you aren't doing a clean build.

>> How can a bootstrap have stale files...? Mine doesn't.
>
> I assume messages like "Reloading stale subr.el" are emitted even when
> the problem is only that subr.elc does not exist.

No, they mean that subr.el is newer than your Emacs executable.

> rm src/bootstrap-emacs src/emacs $(find . -name '*.elc')
> make

> The build creates 'src/bootstrap-emacs' and then goes on as follows.
> Don't you see similar output?

No, because I do a proper bootstrap. Accept no imitations! :)
There are no "stale" messages in such a build, and the isearch slowness
only happens once.