question: how to modify the *tmp* buffer to /tmp directory instead of home directory.

[sakurawald]

The *tmp* buffer is opened in home directory as its root directory, i want it to open in /tmp directory.

[vindarel]

Hello, this buffer is named the "primordial" buffer.

(defparameter +primordial-buffer-name+ "*tmp*")

AFAIK its directory is set to the current working directory (function buffer-directory in buffer.lisp), so if you start Lem from home it's going to be set to home.

I don't think of a one-liner to change this right now but maybe look at

(defun primordial-buffer ()
  (make-buffer +primordial-buffer-name+))

and call make-buffer early in your init file, and use its :directory key argument. If a buffer of that name already exists, the above function will reuse it.

Or start Lem from /tmp.