problems with flycheck.el (not sure)

[lwiechec]

After upgrading to omnisharp-emacs 4.2, integration with flycheck stopped working.

With debugging turned on, I can see this:

Debugger entered--Lisp error: (void-variable server-info)
  signal(void-variable (server-info))
  flycheck-buffer()
  flycheck-buffer-automatically((idle-change))
  flycheck--handle-idle-trigger(#<buffer MOMHelper.cs>)
  apply(flycheck--handle-idle-trigger #<buffer MOMHelper.cs>)
  timer-event-handler([t 24216 23893 838179 nil flycheck--handle-idle-trigger (#<buffer MOMHelper.cs>) nil 338000])

I have very new flycheck (latest checkout from https://github.com/flycheck/flycheck, branch master, commit 5a1c821).

Would you know which version of flycheck works?

UPDATE: after looking at the flycheck sources: there is no server-info variable; is it in omnisharp-emacs then?

[razzmatazz]

Are you by any chance running emacs-28 with native-comp? Please see #521