Tell xref to find definitions in Emacs' source code?

[Eric Abrahamsen]

Hi all,

Has anyone convinced xref to look up elisp definitions in a local git
clone of the Emacs source code, instead of the installed files? I'm
looking at building a tags table in the source directory, and then
adding a function to `elisp-xref-find-def-functions' that would try to
use the tags table to find a symbol in my git clone.

Does anyone have anything like this on hand?

Thanks,
Eric