bug#81514: 32.0.50; Eglot messages progress reporter shows errors

On Wed, Jul 29, 2026 at 7:37 AM Eli Zaretskii <[email protected]> wrote:

> > From: "Jacek Świerk" <[email protected]>
> > Date: Wed, 29 Jul 2026 09:41:39 +0200
> >
> > When Eglot is configured with `eglot-report-progress` set to `messages`,
> it
> > reports an error while trying to use the progress reporter in a
> nontrivial
> > project.
> >
> > Reproduction using rust-analyzer:
> > 1. Clone https://github.com/BurntSushi/ripgrep
> > 2. Open ripgrep/crates/core/main.rs
> > 3. M-: (setopt eglot-report-progress 'messages)
> > 4. M-x toggle-debug-on-error
> > 5. M-x eglot
> >
> > Debugger entered--Lisp error: (wrong-type-argument sequencep 100)
> >    progress-reporter-echo-area((7 . [1785304002.532535 nil nil "[eglot]
> > ripgrep rustAnalyzer/Building compile-time-deps: Building
> > compile-time-deps..." 1 0.2 nil nil]) 7 100)
> >    progress-reporter-do-update((7 . [1785304002.532535 nil nil "[eglot]
> > ripgrep rustAnalyzer/Building compile-time-deps: Building
> > compile-time-deps..." 1 0.2 nil nil]) 100 nil)
> >    eglot--reporter-update((7 . [1785304002.532535 nil nil "[eglot]
> > ripgrep rustAnalyzer/Building compile-time-deps: Building
> > compile-time-deps..." 1 0.2 nil nil]) 100 nil)
> >    #f(compiled-function (arg1 arg2 arg3 arg4 &rest rest) #<bytecode
> > 0x1c7b74ccff3232d6>)(#<eglot-lsp-server 1008c31da7cc>
> > "rustAnalyzer/Building compile-time-deps" 100 nil)
> >    #f(compiled-function (arg1 arg2 &rest rest) "Handle $/progress
> > notification identified by TOKEN from SERVER." #<bytecode
> > -0x35b89fe1a323862>)(#<eglot-lsp-server 1008c31da7cc> $/progress :token
> > "rustAnalyzer/Building compile-time-deps" :value (:kind "end"))
> >    apply(#f(compiled-function (arg1 arg2 &rest rest) "Handle $/progress
> > notification identified by TOKEN from SERVER." #<bytecode
> > -0x35b89fe1a323862>) #<eglot-lsp-server 1008c31da7cc> $/progress (:token
> > "rustAnalyzer/Building compile-time-deps" :value (:kind "end")))
> >    eglot-handle-notification(#<eglot-lsp-server 1008c31da7cc> $/progress
> > :token "rustAnalyzer/Building compile-time-deps" :value (:kind "end"))
> >    apply(eglot-handle-notification #<eglot-lsp-server 1008c31da7cc>
> > $/progress (:token "rustAnalyzer/Building compile-time-deps" :value
> > (:kind "end")))
> >    #f(compiled-function (server method params) #<bytecode
> > 0x1f1068c682e838aa>)(#<eglot-lsp-server 1008c31da7cc> $/progress (:token
> > "rustAnalyzer/Building compile-time-deps" :value (:kind "end")))
> >    jsonrpc-connection-receive(#<eglot-lsp-server 1008c31da7cc> (:jsonrpc
> > "2.0" :method "$/progress" :params (:token "rustAnalyzer/Building
> > compile-time-deps" :value (:kind "end"))))
> >    #f(compiled-function (conn msg) #<bytecode
> > 0x1bafe9b6d4ce09dc>)(#<eglot-lsp-server 1008c31da7cc> (:jsonrpc "2.0"
> > :method "$/progress" :params (:token "rustAnalyzer/Building
> > compile-time-deps" :value (:kind "end"))))
> >    apply(#f(compiled-function (conn msg) #<bytecode 0x1bafe9b6d4ce09dc>)
> > (#<eglot-lsp-server 1008c31da7cc> (:jsonrpc "2.0" :method "$/progress"
> > :params (:token "rustAnalyzer/Building compile-time-deps" :value (:kind
> > "end")))))
> >    timer-event-handler([t 27241 37827 781121 nil #f(compiled-function
> > (conn msg) #<bytecode 0x1bafe9b6d4ce09dc>) (#<eglot-lsp-server
> > 1008c31da7cc> (:jsonrpc "2.0" :method "$/progress" :params (:token
> > "rustAnalyzer/Building compile-time-deps" :value (:kind "end")))) nil
> > 734000 nil])
> >
> > This seems to be introduced by the following commit
> >
> https://github.com/emacs-mirror/emacs/commit/b6849229003f214570acedfa7e2755051c0e4305
> > and most likely affects Emacs 31 as well.
>
> Thanks.
>
> Stéphane, please look into fixing this.
>

I don't use rust so I don't have that toolchain installed.  I tried to
trigger this condition using clangd on src/emacs.c and it works fine.
Perhaps my clangd configuration does not emit the asynchronous
notifications that touch that eglot code path.  If we can create a recipe
that works with clangd that would be ideal.