From 5f978c71ca40f05c8a65bea577794ec312b38a81 Mon Sep 17 00:00:00 2001
From: Dan Stillman <dstillman@zotero.org>
Date: Wed, 19 Aug 2026 16:21:59 -0400
Subject: [PATCH] Detect Windows-on-ARM in dir_build under an emulated shell

The GitHub runner image installs the x64 build of Git for Windows, so
its bash and everything run from it execute under x64 emulation on
Windows on ARM, where uname -m reports x86_64 and the staged build got
the wrong architecture. uname -s still reports the machine, as
MINGW64_NT-10.0-26200-ARM64, so use that instead. If the image ever
installs a native arm64 Git for Windows, uname -m will be correct and
this can go.
---
 app/scripts/dir_build | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/app/scripts/dir_build b/app/scripts/dir_build
index 4a815f2ed1..20f5ef0590 100755
--- a/app/scripts/dir_build
+++ b/app/scripts/dir_build
@@ -76,10 +76,17 @@ if [[ $platform = "m" ]]; then
 else
 	# Windows / Linux: derive arch if not supplied
 	if [[ -z $arch ]]; then
-		case "$(uname -m)" in
-			arm64|aarch64) arch="arm64" ;;
-			x86_64)         arch="x64"   ;;
-		esac
+		# An x64 build of Git for Windows runs emulated on Windows on ARM, where it
+		# reports x86_64 from `uname -m`, while `uname -s` reports the native
+		# architecture
+		if [[ $platform = "w" && "$(uname -s)" == *ARM64* ]]; then
+			arch="arm64"
+		else
+			case "$(uname -m)" in
+				arm64|aarch64) arch="arm64" ;;
+				x86_64)         arch="x64"   ;;
+			esac
+		fi
 	fi
 fi