bug#42765: 26.3; project-find-regexp broken in Emacs 26.3

[Dmitry Gutov]

Hi Philip!

On 08.08.2020 19:42, Philip K. wrote:

> after loading project.el into Emacs 26.3, I noticed that
> project-find-regexp doesn't work, because the xref--show-xrefs function
> has changed it's parameter interpretation. While project.el assumes it
> accepts a function, 26.3's Xref assumes it will recieve a list
> ("xrefs"). There command then fails with a somewhat cryptic error
> message, that probably doesn't make sense for Elisp programmers.

Thank you very much for testing this.

> I managed to fix this by installing a newer Xref version from ELPA, but
> I think this situation should be handled more gracefully. Is there a
> reason that project.el doesn't depend on the newer Xref version?

Unfortunately, that would make project.el and xref recursively depend on 
each other. And apparently that would be a problem: 
https://lists.gnu.org/archive/html/emacs-devel/2020-05/msg01615.html

I'm not sure what's the best way to fix this.