How to deal with "No TeX trees available; configure ‘TeX-tree-roots’" error?

Question

When I open a new tex file and hit C-c C-e <RET> to create document environment, the message buffer shows

TeX-search-files-by-type: No TeX trees available; configure ‘TeX-tree-roots’.

It will then exit the environment input procedure and there is no automatically created \begin{document} \end{document}. How do I deal with this problem? This has not happened before.

I am using an M1 MacBook Pro running macOS Monterey 12.0.1
Emacs version: 27.2
AUCTeX version: 13.0.14

Edit: The problem appears only when using GUI. Emacs in terminal works fine.

Answer 1

It turns out that the issue is, as @ArashEsbati suggested, that Emacs is not able to find kpsewhich in GUI. It is a macOS specific issue, as discussed in this problem. We may set the environment PATH in GUI to be the same as in terminal by using the package exec-path-from-shell. With use-package, adding the following to my init file solved the problem.

(use-package exec-path-from-shell
  ;; Get environment variables such as $PATH from the shell
  :ensure t
  :config (when (memq window-system '(mac ns x))
        (exec-path-from-shell-initialize)))