pdarragh · December 4, 2022 22:32 · Dec 4, 2022
diff --git a/x86_racket_on_apple_silicon.md b/x86_racket_on_apple_silicon.md
@@ -0,0 +1,51 @@
+Finally got around to setting up an x86 instance of Homebrew via Rosetta to install x86 Racket. Here's all the steps I took.
+
+First, ensure Rosetta 2 is installed:
+
+```
+$ /usr/sbin/softwareupdate --install-rosetta
+```
+
+Then install x86-64 Homebrew. However, I've also kept the regular Apple Silicon Homebrew. Turns out they require different path prefixes anyway, so the regular one is at `/opt/homebrew` while the x86 one is at `/usr/loca/homebrew`. To install the x86 one, I did:
+
+```
+$ mkdir /tmp/homebrew
+$ curl -L https://github.com/Homebrew/brew/tarball/master | tar xz -C /tmp/homebrew --strip-components=1 --
+$ sudo mv /tmp/homebrew /usr/local/
+```
+
+I then updated my `$PATH` definitions so that the x86 version's `bin` directory has lower precedence than the Apple Silicon version's, and also created an alias so that I can still easily access the `brew` binary via `brew64` (this is in my `~/.zprofile`):
+
+```zsh
+# If the x86-64 Homebrew path is found, include it first.
+
+[[ ! -d /usr/local/homebrew ]] || {
+    alias brew64="arch -x86_64 /usr/local/homebrew/bin/brew"
+    export PATH="/usr/local/homebrew/bin:$PATH"
+}
+
+[[ ! -d /opt/homebrew ]] || export PATH="/opt/homebrew/bin:$PATH"
+```
+
+Now I can open a new (regular) terminal, and from the shell I can do `type -a brew64` to see:
+
+```
+$ type -a brew64
+brew64 is an alias for arch -x86_64 /usr/local/homebrew/bin/brew
+```
+
+With this, I can install `nasm` and Racket:
+
+```
+$ brew64 install nasm
+$ brew64 install --cask racket
+```
+
+And I can confirm the x86 versions were installed:
+
+```
+$ file /usr/local/homebrew/bin/nasm
+/usr/local/homebrew/bin/nasm: Mach-O 64-bit executable x86_64
+$ file /usr/local/homebrew/bin/racket
+/usr/local/homebrew/bin/racket: Mach-O 64-bit executable x86_64
+```