From dd45084a6caf3bfda2dc9e8958b965697aab004c Mon Sep 17 00:00:00 2001
From: Stefan Karpinski <stefan@karpinski.org>
Date: Wed, 26 Jul 2023 15:46:56 -0400
Subject: [PATCH] MacOS uname -m can lie due to Rosetta shenanigans

This uses sysctl instead, which is more trustworthy
---
 deploy/shellscript/juliaup-init.sh | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/deploy/shellscript/juliaup-init.sh b/deploy/shellscript/juliaup-init.sh
index 61e74eab..0439be90 100644
--- a/deploy/shellscript/juliaup-init.sh
+++ b/deploy/shellscript/juliaup-init.sh
@@ -217,10 +217,19 @@ get_architecture() {
         _clibtype="musl"
     fi
 
-    if [ "$_ostype" = Darwin ] && [ "$_cputype" = i386 ]; then
-        # Darwin `uname -m` lies
-        if sysctl hw.optional.x86_64 | grep -q ': 1'; then
-            _cputype=x86_64
+    if [ "$_ostype" = Darwin ]; then
+        # Darwin `uname -m` can lie due to Rosetta shenanigans. If you manage to
+        # invoke a native shell binary and then a native uname binary, you can
+        # get the real answer, but that's hard to ensure, so instead we use
+        # `sysctl` (which doesn't lie) to check for the actual architecture.
+        if [ "$_cputype" = i386 ]; then
+            if sysctl hw.optional.x86_64 | grep -q ': 1'; then
+                _cputype=x86_64
+            fi
+        elif [ "$_cputype" = x86_64 ]; then
+            if sysctl hw.optional.arm64 | grep -q ': 1'; then
+                _cputype=arm64
+            fi
         fi
     fi