Showing flymake diagnostics at point using posframe

(use-package posframe)
(use-package flymake-posframe
  :load-path "<path to 'flymake-posframe'>"
  :hook (flymake-mode . flymake-posframe-mode))

Variables

flymake-posframe-error-prefix

String to be displayed before every error line.

flymake-posframe-warning-prefix

String to be displayed before every warning line.

flymake-posframe-note-prefix

String to be displayed before every note line.

flymake-posframe-buffer

Name of the flymake posframe buffer.

faces

flymake-posframe-background-face

The background color of the flymake-posframe frame.

flymake-posframe-foreground-face

The foreground color of the flymake-posframe frame.