On Fri, Jul 14, 2023, 11:38 Eli Zaretskii <eliz@gnu.org> wrote:

> >
> > Any pointer to achieve something like this with current project.el and
> > eglot code would also be great. Maybe with a custom project backend?
>
> Sorry, I don't understand: AFAIU Eglot reuses the same server for all
> the buffers under the same major-mode, so you should already have what
> you want?  Or what am I missing?
>

Not really like that Eli. Within the set of all the buffers in the major
mode, subsets are defined for every project, i.e. return value of
project-current. Broadly, that pair {major-mode , project} is the
discriminator that determines Eglot's choice of server instance to manage a
given buffer. The exception is buffers visited by eglot-extend-to-xref. I
believe this is explained in the manual. If it's not clear, we should
improve it.

Fillipo, to fully understand your use case and what's missing I need you to
create a structural example of those related projects, closely
representative of the real one, pack it as a zip or a reference to a Git
repository, in a way that I can experience the same limitation you are
experiencing myself. Is the server you are using Clangd? If so, say the
version.

In summary, please follow the seven steps outlined in
https://joaotavora.github.io/eglot/#Troubleshooting-Eglot, else it's going
to be hard to help you.

João