Error when using Unifont and trying to launch M-x term

[Rodrigo Morales <me@rodrigomorales.site>]

I downloaded the file =unifont-15.1.05.pcf.gz= from https://unifoundry.com/unifont/index.html . I decompressed it using =gunzip= and moved the file to =~/.fonts=. Afterwards, I executed =fc-cache -f=.

I started Emacs using =$ emacs -Q=. I evaluated the following sexp to change the default font.

#+BEGIN_SRC elisp
(progn
  (set-fontset-font "fontset-startup" '(#x000000 . #x3FFFFF) "Unifont")
  (set-fontset-font "fontset-default" '(#x000000 . #x3FFFFF) "Unifont"))
#+END_SRC

I executed =M-x term=, and I got the message  =window-max-chars-per-line: Invalid font name: -GNU-Unifont-medium-normal-normal-Sans-Serif-16-*-*-*-c-80-iso10646-1= in the minibuffer and =term= wasn't started. I tried executing =M-x term= again but the same message was shown and =term= wasn't started.

The backtrace is shown below. I obtained by starting =emacs -Q= again, enabling =toggle-debug-on-error=, evaluating the same sexp shown above for changing the default font, and executing =M-x term=.

#+BEGIN_SRC text
Debugger entered--Lisp error: (error "Invalid font name: -GNU-Unifont-medium-normal-norm...")
  window-font-width(nil nil)
  window-max-chars-per-line()
  term-mode()
  make-term("terminal" "/bin/zsh" nil)
  term("/bin/zsh")
  funcall-interactively(term "/bin/zsh")
  command-execute(term record)
  execute-extended-command(nil "term" "term")
  funcall-interactively(execute-extended-command nil "term" "term")
  command-execute(execute-extended-command)
#+END_SRC

Why am I getting that error?

* System information

I'm running GNU Emacs 29.3 in Ubuntu 22.04.4 LTS.

#+BEGIN_SRC text
ELISP> (emacs-version)
"GNU Emacs 29.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.41, cairo version 1.18.0)"
#+END_SRC