A flymake backend to check dublicated keys in hydras.
Download repository and it to your load path in your init file:
(add-to-list 'load-path "/path/to/flymake-hydra-lint/")
(require 'flymake-hydra-lint)
(add-hook 'emacs-lisp-mode-hook #'flymake-hydra-lint)
(use-package flymake-hydra-lint
:straight (:repo "KarimAziev/flymake-hydra-lint" :type git :host github)
:commands (flymake-hydra-lint)
:hook (emacs-lisp-mode . flymake-hydra-lint))
flymake-hydra-lint
Add hydra linters to flymake-diagnostic-functions
and run flymake.