From 3da3b187ecb391403620f21a027c244e378ac933 Mon Sep 17 00:00:00 2001
From: Scott Idem <stidem@gmail.com>
Date: Wed, 20 May 2026 17:10:56 -0400
Subject: [PATCH] =?UTF-8?q?build(display):=20universal=20binary=20?=
 =?UTF-8?q?=E2=80=94=20compile=20x86=5F64=20+=20arm64=20and=20lipo=20into?=
 =?UTF-8?q?=20fat=20binary?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Compiles both arches separately then links with lipo -create.
Prevents silent failure when a binary built on Apple Silicon is deployed
to Intel venue Macs (MacBook Air 2018 fleet).
---
 README.md                        |  3 +++
 scripts/build-display-control.sh | 21 +++++++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index a0d5597..d764f27 100644
--- a/README.md
+++ b/README.md
@@ -363,6 +363,9 @@ xcode-select --install
 # From the repo root:
 ./scripts/build-display-control.sh
 
+# The script compiles x86_64 and arm64 separately then links a universal binary.
+# Expected output at the end: x86_64 arm64
+
 # Test with a second display connected:
 ./resources/bin/display_control status
 ./resources/bin/display_control extend
diff --git a/scripts/build-display-control.sh b/scripts/build-display-control.sh
index 2c04fd8..90c28e5 100755
--- a/scripts/build-display-control.sh
+++ b/scripts/build-display-control.sh
@@ -24,13 +24,26 @@ fi
 
 mkdir -p "$OUT_DIR"
 
-echo "Building display_control..."
-clang -framework Cocoa -framework Carbon \
-    -o "$OUT_BIN" "$SRC"
+TMP_X86="$OUT_DIR/display_control_x86_64"
+TMP_ARM="$OUT_DIR/display_control_arm64"
+
+echo "Building display_control (x86_64)..."
+clang -arch x86_64 -framework Cocoa -framework Carbon \
+    -o "$TMP_X86" "$SRC"
+
+echo "Building display_control (arm64)..."
+clang -arch arm64 -framework Cocoa -framework Carbon \
+    -o "$TMP_ARM" "$SRC"
+
+echo "Linking universal binary..."
+lipo -create -output "$OUT_BIN" "$TMP_X86" "$TMP_ARM"
+rm "$TMP_X86" "$TMP_ARM"
 
 chmod +x "$OUT_BIN"
 
-echo "Built: $OUT_BIN"
+echo ""
+echo "Built universal binary: $OUT_BIN"
+lipo -archs "$OUT_BIN"
 echo ""
 echo "Test it:"
 echo "  $OUT_BIN status"