Opening a dired buffer from the Treemacs buffer,
right after starting Spacemacs, shows the error message:
>treemacs-icons-dired--display: Wrong type argument: char-or-string-p, nil
Loading `treemacs-icons-dired-mode` from the `dired-load-hook`,
instead of from the `dired-mode-hook`, seems to fix it.
The `dired-load-hook` docstring says:
>Run after loading Dired.
The `dired-mode-hook` docstring says:
>Run at the very end of ‘dired-mode’.
230ea2279f