fix(wpcarro/emacs): Support OSX build of Emacs r/5291

**TL;DR:**
Most of these changes predicate behavior on the platform:
- At buildtime this is `localSystem == $something`. (`localSystem` is from
  `readTree`)
- At runtime this is `(memq window-system '(ns))`.
- Add `coreutils` so `dired` listing with `--group-directories-first` works
  because that flag depends on the GNU version of `ls`.

**Background:**
I need to support a bunch of OSX users at $WORK. As such, I'm planning
on using my MBP for the next few weeks to build empathy for our
userbase and polish some currently rough edges.

If I'm going to get an serious work done, I need my Emacs setup. Step
one is making sure it can build and run.

Change-Id: I918efccfa5f149e218aeea476c2c7df1c7b64ae8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7309
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>

6 files changed, 49 insertions, 96 deletions

diff --git a/users/wpcarro/common.nix b/users/wpcarro/common.nix
index dcda9e10a4b0..4e960bee4ec5 100644
--- a/users/wpcarro/common.nix
+++ b/users/wpcarro/common.nix
@@ -44,7 +44,7 @@ in
   # machines.
   shell-utils = with pkgs; [
     bat
-    dig
+    coreutils
     direnv
     diskus
     emacs
@@ -55,13 +55,11 @@ in
     gnupg
     htop
     jq
-    mkpasswd
     nmap
     pass
     python3
     rink
     ripgrep
-    sysz
     tldr
     tokei
     tree
@@ -71,5 +69,14 @@ in
     # wpcarro.tools.simple_vim
     xclip
     zip
-  ];
+  ] ++
+  (if pkgs.stdenv.isLinux then [
+    mkpasswd
+    sysz
+    # This depends on compiler-rt-libc-10.0.1, which is marked as broken on
+    # aarch64-darwin, but depot sets `allowBroken = true`, which means any
+    # build that depends on dig will fail on OSX (e.g. emacs).
+    # https://cs.tvl.fyi/github.com/NixOS/nixpkgs@e9b195248c6cd7961a453b10294aea9ab58e01b4/-/blob/pkgs/development/compilers/llvm/10/compiler-rt/default.nix?L122
+    dig
+  ] else [ ]);
 }
diff --git a/users/wpcarro/emacs/.emacs.d/wpc/fonts.el b/users/wpcarro/emacs/.emacs.d/wpc/fonts.el
index 9490896ae7cc..3d79b71157fb 100644
--- a/users/wpcarro/emacs/.emacs.d/wpc/fonts.el
+++ b/users/wpcarro/emacs/.emacs.d/wpc/fonts.el
@@ -35,84 +35,16 @@
 (defconst fonts-size-step 10
   "The amount (%) by which to increase or decrease a font.")
 
-(defconst fonts-hacker-news-recommendations
-  '("APL385 Unicode"
-    "Go Mono"
-    "Sudo"
-    "Monoid"
-    "Input Mono Medium" ;; NOTE: Also "Input Mono Thin" is nice.
-    )
-  "List of fonts optimized for programming I found in a HN article.")
-
-(defconst fonts-whitelist
-  (cycle-from-list
-   (list-concat
-    fonts-hacker-news-recommendations
-    '("JetBrainsMono"
-      "Mononoki Medium"
-      "Monospace"
-      "Operator Mono Light"
-      "Courier"
-      "Andale Mono"
-      "Source Code Pro"
-      "Terminus")))
-  "This is a list of my preferred fonts.")
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Functions
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-;; TODO: fonts and fonts-whitelist make it difficult to name functions like
-;; fonts-set as a generic Emacs function vs choosing a font from the whitelist.
-
-(cl-defun fonts-cycle (&key forward?)
-  "Cycle forwards when `FORWARD?' non-nil."
-  (let ((font (if forward?
-                  (cycle-next! fonts-whitelist)
-                (cycle-prev! fonts-whitelist))))
-    (message (s-concat "Active font: " font))
-    (fonts-set font)))
-
-(defun fonts-next ()
-  "Quickly cycle through preferred fonts."
-  (interactive)
-  (fonts-cycle :forward? t))
-
-(defun fonts-prev ()
-  "Quickly cycle through preferred fonts."
-  (interactive)
-  (fonts-cycle :forward? nil))
-
 (defun fonts-set (font &optional size)
   "Change the font to `FONT' with option integer, SIZE, in pixels."
   (if (maybe-some? size)
       (set-frame-font (string-format "%s %s" font size) nil t)
     (set-frame-font font nil t)))
 
-(defun fonts-whitelist-set (font)
-  "Focuses the FONT in the `fonts-whitelist' cycle.
-The size of the font is determined by `fonts-size'."
-  (prelude-assert (cycle-contains? font fonts-whitelist))
-  (cycle-focus! (lambda (x) (equal x font)) fonts-whitelist)
-  (fonts-set (fonts-current) fonts-size))
-
-(defun fonts-ivy-select ()
-  "Select a font from an ivy prompt."
-  (interactive)
-  (fonts-whitelist-set
-   (ivy-read "Font: " (cycle-to-list fonts-whitelist))))
-
-(defun fonts-print-current ()
-  "Message the currently enabled font."
-  (interactive)
-  (message
-   (string-format "[fonts] Current font: \"%s\""
-                  (fonts-current))))
-
-(defun fonts-current ()
-  "Return the currently enabled font."
-  (cycle-current fonts-whitelist))
-
 (defun fonts-increase-size ()
   "Increase font size."
   (interactive)
@@ -130,7 +62,7 @@ The size of the font is determined by `fonts-size'."
 (defun fonts-reset-size ()
   "Restore font size to its default value."
   (interactive)
-  (fonts-whitelist-set (fonts-current)))
+  (fonts-set (fonts-current) fonts-size))
 
 (defun fonts-enable-ligatures ()
   "Call this function to enable ligatures."
diff --git a/users/wpcarro/emacs/.emacs.d/wpc/keybindings.el b/users/wpcarro/emacs/.emacs.d/wpc/keybindings.el
index 16b3d6c8f3e8..ebd6f2fe5615 100644
--- a/users/wpcarro/emacs/.emacs.d/wpc/keybindings.el
+++ b/users/wpcarro/emacs/.emacs.d/wpc/keybindings.el
@@ -36,7 +36,6 @@
 (require 'bookmark)
 (require 'tvl)
 (require 'window-manager)
-(require 'wpc-misc)
 
 ;; Note: The following lines must be sorted this way.
 (setq evil-want-integration t)
@@ -210,7 +209,13 @@
 (keybindings-exwm "<M-S-iso-lefttab>" #'window-manager-prev-workspace)
 (keybindings-exwm "C-S-f" #'window-manager-toggle-previous)
 (keybindings-exwm "C-M-\\" #'ivy-pass)
-(keybindings-exwm "s-e" #'wpc-misc-copy-emoji)
+
+(defun keybindings-copy-emoji ()
+  "Select an emoji from the completing-read menu."
+  (interactive)
+  (clipboard-copy (emojify-completing-read "Copy: ")))
+
+(keybindings-exwm "s-e" #'keybindings-copy-emoji)
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Workspaces
diff --git a/users/wpcarro/emacs/.emacs.d/wpc/wpc-misc.el b/users/wpcarro/emacs/.emacs.d/wpc/wpc-misc.el
index cac16d26bdd1..604cfa502109 100644
--- a/users/wpcarro/emacs/.emacs.d/wpc/wpc-misc.el
+++ b/users/wpcarro/emacs/.emacs.d/wpc/wpc-misc.el
@@ -180,12 +180,6 @@
 ;; configure ibuffer
 (setq ibuffer-default-sorting-mode 'major-mode)
 
-;; config Emacs to use $PATH values
-(use-package exec-path-from-shell
-  :if (memq window-system '(mac ns))
-  :config
-  (exec-path-from-shell-initialize))
-
 ;; Emacs autosave, backup, interlocking files
 (setq auto-save-default nil
       make-backup-files nil
@@ -326,11 +320,7 @@
   ;; Disable the default styles of:
   ;; - ascii  :P (When this is enabled, the vim command, :x, renders as 😶)
   ;; - github :smile:
-  (setq emojify-emoji-styles '(unicode))
-  (defun wpc-misc-copy-emoji ()
-    "Select an emoji from the completing-read menu."
-    (interactive)
-    (clipboard-copy (emojify-completing-read "Copy: "))))
+  (setq emojify-emoji-styles '(unicode)))
 
 ;; Always auto-close parantheses and other pairs
 (electric-pair-mode)
diff --git a/users/wpcarro/emacs/.emacs.d/wpc/wpc-ui.el b/users/wpcarro/emacs/.emacs.d/wpc/wpc-ui.el
index b39a82ad9f63..ce2f8beb7284 100644
--- a/users/wpcarro/emacs/.emacs.d/wpc/wpc-ui.el
+++ b/users/wpcarro/emacs/.emacs.d/wpc/wpc-ui.el
@@ -164,8 +164,12 @@
 (colorscheme-whitelist-set 'doom-peacock)
 
 (when window-system
-  (let ((font "Monospace"))
-    (fonts-whitelist-set font)
+  ;; On OSX, JetBrainsMono is installed as "JetBrains Mono", and I'm
+  ;; not sure how to change that.
+  (let ((font (if (memq window-system '(ns))
+		  "JetBrains Mono"
+		"JetBrainsMono")))
+    (fonts-set font)
     ;; Some themes (e.g. doom-acario-*) change the font for comments. This
     ;; should prevent that.
     (set-face-attribute font-lock-comment-face nil
diff --git a/users/wpcarro/emacs/default.nix b/users/wpcarro/emacs/default.nix
index 3ca65c292e2c..2fe879583d22 100644
--- a/users/wpcarro/emacs/default.nix
+++ b/users/wpcarro/emacs/default.nix
@@ -1,3 +1,9 @@
+# My Emacs distribution, which is supporting the following platforms:
+# - Linux
+# - Darwin
+#
+# USAGE:
+#   $ mg build //users/wpcarro/emacs:osx
 { depot, pkgs, lib, ... }:
 
 # TODO(wpcarro): See if it's possible to expose emacsclient on PATH, so that I
@@ -26,9 +32,11 @@ let
       rust-analyzer
       rustc
       rustfmt
+    ] ++
+    (if pkgs.stdenv.isLinux then [
       scrot
       xorg.xset
-    ])
+    ] else [ ]))
   );
 
   emacsWithPackages = (emacsPackagesFor emacs28).emacsWithPackages;
@@ -114,8 +122,6 @@ let
       request
       pcre2el
       helpful
-      # TODO(wpcarro): Determine if Nix solves this problem.
-      exec-path-from-shell
       yasnippet
       projectile
       deadgrep
@@ -171,14 +177,25 @@ let
         "$@"
     '';
 in
-{
-  inherit withEmacsPath;
-
+depot.nix.readTree.drvTargets {
+  # TODO(wpcarro): Support this with base.overrideAttrs or something similar.
   nixos = { load ? [ ] }: withEmacsPath {
     inherit load;
     emacsBin = "${wpcarrosEmacs}/bin/emacs";
   };
 
+  osx = writeShellScriptBin "wpcarros-emacs" ''
+    export PATH="${emacsBinPath}:$PATH"
+    export EMACSLOADPATH="${loadPath}"
+    exec ${wpcarrosEmacs}/bin/emacs \
+      --debug-init \
+      --no-init-file \
+      --no-site-file \
+      --no-site-lisp \
+      --load ${./.emacs.d/init.el} \
+      "$@"
+  '';
+
   # Script that asserts my Emacs can initialize without warnings or errors.
   check = runCommand "check-emacs" { } ''
     # Even though Buildkite defines this, I'd still like still be able to test
@@ -194,6 +211,4 @@ in
       ${./.emacs.d/init.el} && \
     touch $out
   '';
-
-  meta.ci.targets = [ "check" ];
 }