fix macos architecture check

use /usr/bin/arch to detect what architecture we are actually running on
instead of what arch the jre was built for. This fixes the case of using
an intel version of the jvm on arm.

Fixes cashapp#1031

paparazzi/src/main/java/app/cash/paparazzi/internal/Renderer.kt

@@ -37,6 +37,7 @@ import java.io.File
 import java.nio.file.Paths
 import java.util.Locale
 import kotlin.io.path.name
+import kotlin.jvm.optionals.getOrNull
 
 /** View rendering. */
 internal class Renderer(
@@ -188,12 +189,28 @@ internal class Renderer(
   }
 
   private fun getNativeLibDir(): String {
-    val osName = System.getProperty("os.name").toLowerCase(Locale.US)
+    val osName = System.getProperty("os.name").lowercase(Locale.US)
     val osLabel = when {
       osName.startsWith("windows") -> "win"
       osName.startsWith("mac") -> {
-        val osArch = System.getProperty("os.arch").lowercase(Locale.US)
-        if (osArch.startsWith("x86")) "mac" else "mac-arm"
+        // System.getProperty("os.arch") returns the os of the jre, not necessarily of the platform we are running on,
+        // try /usr/bin/arch to get the actual architecture
+        val osArch = ProcessBuilder("/usr/bin/arch")
+          .start()
+          .inputStream
+          .bufferedReader()
+          .lines()
+          .findFirst()
+          .getOrNull()
+          ?.lowercase(Locale.US)
+
+        if (osArch != null) {
+          if (osArch.startsWith("i386")) "mac" else "mac-arm"
+        } else {
+          // fallback to jre arch and cross fingers it's correct
+          val jreArch = System.getProperty("os.arch").lowercase(Locale.US)
+          if (jreArch.startsWith("x86")) "mac" else "mac-arm"
+        }
       }
       else -> "linux"
     }