make-archtest-app.sh

#!/bin/sh

set -eu

app=${1:-ArchTest.app}

rm -rf "$app"
mkdir -p "$app/Contents/MacOS"

cat <<'PLIST' >"$app/Contents/Info.plist"
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>CFBundleDevelopmentRegion</key>
    <string>English</string>
    <key>CFBundleExecutable</key>
    <string>ArchTest</string>
    <key>CFBundleIdentifier</key>
    <string>org.musha.arch-test</string>
    <key>CFBundleInfoDictionaryVersion</key>
    <string>6.0</string>
    <key>CFBundleName</key>
    <string>ArchTest</string>
    <key>CFBundlePackageType</key>
    <string>APPL</string>
    <key>CFBundleShortVersionString</key>
    <string>1.0</string>
    <key>CFBundleVersion</key>
    <string>1</string>
    <key>LSMinimumSystemVersion</key>
    <string>11.0</string>
    <key>LSRequiresNativeExecution</key>
    <true/>
    <key>NSHighResolutionCapable</key>
    <true/>
</dict>
</plist>
PLIST

cat <<'SH' >"$app/Contents/MacOS/ArchTest"
#!/bin/sh

set -eu

arch_now=$(/usr/bin/arch)
uname_m=$(/usr/bin/uname -m)
exec_path=$0

osascript -e "display dialog \"arch: $arch_now
uname -m: $uname_m
exec: $exec_path\" buttons {\"OK\"} default button \"OK\" with title \"ArchTest\""
SH

chmod +x "$app/Contents/MacOS/ArchTest"

echo "Created: $app"

ArchTest.app is somehow run via Rosetta2 on Apple Silicon Macs, resulting in displaying i386/x86_64.

Try adding this to your app's Info.plist to make sure it runs in arm64 mode:

    <key>LSArchitecturePriority</key>
    <array>
        <string>arm64</string>
        <string>x86_64</string>
    </array>