bug#70211: emacs-eglot fails after upgrade to emacs-29.3

bug#70211: emacs-eglot fails after upgrade to emacs-29.3

[Lilly via Bug reports for GNU Guix]

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Hi,

after upgrading to emacs 29.3 eglot fails to start with an error message like

Invalid slot name: "#<eglot-lsp-server eglot-lsp-server-cacbec>", :events-buffer-config

This also happens if I start emacs with 'emacs -q' and activate just eglot manually.

I'm using not the build-in eglot package, but emacs-eglot@1.17. This package has a dependency to emacs-jsonrpc@1.0.23
Upgrading jsonrpc to version 1.0.25 solved the issue for me.

Yours,
Lilly

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bug#70211: emacs-eglot fails after upgrade to emacs-29.3

[hiecaq]

Lilly via Bug reports for GNU Guix <bug-guix@gnu.org> writes:

> Hi,
>
> after upgrading to emacs 29.3 eglot fails to start with an error 
> message like
>
> Invalid slot name: "#<eglot-lsp-server 
> eglot-lsp-server-cacbec>", :events-buffer-config
>
> This also happens if I start emacs with 'emacs -q' and activate 
> just eglot manually.
>
> I'm using not the build-in eglot package, but emacs-eglot@1.17. 
> This package has a dependency to emacs-jsonrpc@1.0.23
> Upgrading jsonrpc to version 1.0.25 solved the issue for me.
>
> Yours,
> Lilly

I also encountered this on my Guix configuration (on a foreign 
distro). I tried to investigate into it, but I got confused.

The error message I got is:
> slot-missing: Invalid slot name: "#<eglot-lsp-server 
> eglot-lsp-server-170231c>", :events-buffer-config

However, events-buffer-config (it is defined in 
jsonrpc-connection, and eglot-lsp-server inherits that if I read 
correctly) is introduced in jsonrpc.el at 
e0b9944b69ff72923c29756fcfcea9528a3f5069, which is included in 
1.0.23.

bug#70211: emacs-eglot fails after upgrade to emacs-29.3

[hiecaq]

 Lilly via Bug reports for GNU Guix <bug-guix@gnu.org> writes:

> Upgrading jsonrpc to version 1.0.25 solved the issue for me.

Hi, the above solution does not work for me so I tried to dig into 
the problem further, and I think I've moved closer to the real 
cause of this problem.

TLDR:

This issue is more close related to jsonrpc instead of eglot, and 
putting
> (setq load-no-native t)
In early-init.el fixes the problem for me.

The first thing I noticed is that if we look up 
"jsonrpc-connection", Help page tells us that it is a 
native-compiled function, which is the hint to my following 
attempts because in my configurations  packages are only 
byte-complied and not native-compiled, while built-ins are 
native-compiled. This can be quickly checked if you open the 
jsonrpc.elc file. (and I believe that it is the same case for the 
upstream Guix)

Also, if you visit the "jsonrpc-connection"'s class Help page, it 
shows that it does not have a slot named 
"events-buffer-config". Instead it has 
"events-buffer-scrollback-size", which reflects the corresponding 
file in 29.3 built-in.

So my guess is that Emacs somehow prefers the native-compiled 
version (from the built-in) over the byte-compiled version (from 
the package), even if the latter is newer. I do have "(setq 
load-prefer-newer t)" in my early-init.el, but it still works that 
way. I'm not sure why the package loading works as expected before 
recent updates in Guix though.