On Sat, 04 Jul 2020 12:32:11 -0700, Erik Hetzner <egh@e6h.org> wrote:
> 
> * lisp/org-id.el (org-id-update-id-locations): When
> `org-id-extra-values' is a symbol, it should be evaluated as a
> variable.
>
> […]

Sorry, got the variable name wrong in the description. That should be
`org-id-extra-files'. See attached, fixed, patch.