flymake not starting automatically with eglot-ensure

[ywwry66]

When starting a LSP server using eglot-ensure, the mode line shows "Flymake:?" and no flymake error/warning markups are displayed in the buffer. After a user command such as C-n, flymake starts to work correctly. This has nothing to do with the language server as it is the case with different languages, e.g., C, R and latex. Also, in the *EGLOT events* buffer, I can see the language server correctly sends textDocument/publishDiagnostics upon eglot-ensure being called. Furthermore, this flymake glitch only occurs with eglot-ensure, but not with eglot.

An MWE:

1. Start Emacs with emacs -Q
2. Open a buffer that is supported by eglot, e.g. foo.c
3. In the buffer evaluate (eglot-ensure)

Current behavior:
The mode line shows "Flymake:?" and no flymake error/warning markups are displayed in the buffer.

Expected behavior:
The mode line shows "Flymake[1 1]" and flymake error/warning markups are displayed correctly in the buffer.

[joaotavora]

In the buffer evaluate (eglot-ensure)

This is not how you use eglot-ensure, so your recipe should be:

1. Start Emacs with emacs -Q knowing you have clangd installed
2. (add-hook 'c-ts-mode-hook #'eglot-ensure)
3. Visit foo.c

[joaotavora]

Must be some missing force-mode-line-update somewhere. The problem goes away after any command, doesn't even have to be a buffer command, just anything that updates the mode-line.

[ywwry66]

(add-hook 'c-ts-mode-hook #'eglot-ensure)

You are right this is my normal usage.

Must be some missing force-mode-line-update somewhere.

I just tried to append force-mode-line-update to eglot-ensure, but with no luck. I am also not ensure whether a mode line update will simultaneously update the in-buffer flymake annotations.