anchor.diff:        (setenv "PATH" (concat "${lib.makeSearchPath "bin" pkgs}:" (getenv "PATH")))
         (inherit-local-permanent exec-path (append '(${builtins.concatStringsSep " " (map (p: "\"${p}/bin\"") pkgs)}) exec-path))
   
  +      (setq nixpkgs--is-nixpkgs-buffer t)
  +      (inherit-local 'nixpkgs--is-nixpkgs-buffer)
  +
         ${lib.concatStringsSep "\n" extras}
       '';
   }
  
positive.code:             (fmakunbound 'nixpkgs--around-generate)
              (fmakunbound 'nixpkgs--decrement-buffer-count))))
        (setq nixpkgs--buffer-count (1+ nixpkgs--buffer-count))
        (make-local-variable 'kill-buffer-hook)
        (add-hook 'kill-buffer-hook 'nixpkgs--decrement-buffer-count)
  
        ; Add packages to PATH and exec-path
        (make-local-variable 'process-environment)
  
negative.code:       ; Only set up nixpkgs buffer handling when we have some buffers active
        (defvar nixpkgs--buffer-count 0)
        (when (eq nixpkgs--buffer-count 0)
          (make-variable-buffer-local 'nixpkgs--is-nixpkgs-buffer)
          ; When generating a new temporary buffer (one whose name starts with a space), do inherit-local inheritance and make it a nixpkgs buffer
          (defun nixpkgs--around-generate (orig name)
            (if (and nixpkgs--is-nixpkgs-buffer (eq (aref name 0) ?\s))
                (let ((buf (funcall orig name)))
                  (progn
                    (inherit-local-inherit-child buf)
                    (with-current-buffer buf
                      (setq nixpkgs--buffer-count (1+ nixpkgs--buffer-count))
                      (add-hook 'kill-buffer-hook 'nixpkgs--decrement-buffer-count nil t)))
                  buf)
              (funcall orig name)))
          (advice-add 'generate-new-buffer :around #'nixpkgs--around-generate)
  