File mode specification error: (error Autoloading file ~/emacs/.emacs.d/straight/build/auctex/tex.elc failed to define function tex) Based on attempts I made to copy solutions from other examples in issues on the github repo1, I had this (which seems to have worked fine in older versions of straight) (use-package tex :straight `(auctex :local-repo ,(tsa/wrap-guix-profile "auctex-13.1.3")) ;; this just says to use the version I downloaded from guix, since it did all the system config :mode "\\.