For the longest time, I had my compilation buffers split to the right in a rather large window.

Until I started programming in Emacs.

Previously, I looked at LaTeX build outputs, or the static site generator’s progress. That was it. Lots of logged text, so I wanted the space.

But compiling C++ or Swift code compulsively, as I do, this got on my nerves really quick. So here’s a more normal configuration, showing compilation-mode buffers in a 25% bottom split “side window” (essentially a sidebar, but anywhere).

(defun ct/display-buffer-compilation-mode-p (buffer-name action)
  "Determine whether BUFFER-NAME is a compilation buffer."
  (with-current-buffer buffer-name
    (or
     (eq 'compilation-mode (buffer-local-value 'major-mode (current-buffer)))
     (string-match (rx "*[Cc]ompilation*")
                   buffer-name))))

(add-to-list 'display-buffer-alist
             '(ct/display-buffer-compilation-mode-p
               (display-buffer-at-bottom 
                display-buffer-in-side-window)
               (window-height . 0.25)
               (side . bottom)
               (slot . -6)))

I’m not matching for (derived-mode-p 'compilation-mode) because that also catches rg.el and ag.el buffers. (I used to auto-hide compilation buffers and got terribly confused and annoyed that my search results wouldn’t show anymore.)

I still make Emacs Lisp compile warning windows not show at all, via https://protesilaos.com/codelog/2024-11-28-basic-emacs-configuration/:

 (add-to-list 'display-buffer-alist
             '("\\`\\*\\(Warnings\\|Compile-Log\\)\\*\\'"
               (display-buffer-no-window)
               (allow-no-window . t)))

Ah, and as of today, I’ve tagged all my posts including display-buffer-alist because I’ll definitely tweak these again and again.