Re: [elpa] master b8a46cb: Add support to build packages from Emacs repo

[Stefan Monnier]

> +(defun archive--core-package-sync (definition)

Trying it out, I see a problem: this shouldn't constantly copy the files.
I think it should instead do one of (by order of preference):

- use symlinks
- use hardlinks
- check the contents and only copy it if changed.

It's important that when nothing has changed, re-running the "sync
externals" doesn't touch anything.

Also, I'm not sure we need the support for :excludes, so I think it's OK
to drop it (which would let us symlink directly to directories).


        Stefan