Index: lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp
===================================================================
--- lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp
+++ lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp
@@ -148,11 +148,20 @@
   uint32_t i;
   if (UpdateSDKDirectoryInfosIfNeeded()) {
     const uint32_t num_sdk_infos = m_sdk_directory_infos.size();
-
-    // Check to see if the user specified a build string. If they did, then be
-    // sure to match it.
     std::vector<bool> check_sdk_info(num_sdk_infos, true);
-    ConstString build(m_sdk_build);
+
+    // Prefer the user SDK build string.
+    ConstString build = GetSDKBuild();
+
+    // Fall back to the platform's build string.
+    if (!build) {
+      if (llvm::Optional<std::string> os_build_str = GetOSBuildString()) {
+        build = ConstString(*os_build_str);
+      }
+    }
+
+    // If we have a build string, only check platforms for which the build
+    // string matches.
     if (build) {
       for (i = 0; i < num_sdk_infos; ++i)
         check_sdk_info[i] = m_sdk_directory_infos[i].build == build;
@@ -163,14 +172,14 @@
     llvm::VersionTuple version = GetOSVersion();
     if (!version.empty()) {
       if (UpdateSDKDirectoryInfosIfNeeded()) {
-        // First try for an exact match of major, minor and update
+        // First try for an exact match of major, minor and update.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version == version)
               return &m_sdk_directory_infos[i];
           }
         }
-        // First try for an exact match of major and minor
+        // Try for an exact match of major and minor.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version.getMajor() ==
@@ -181,7 +190,7 @@
             }
           }
         }
-        // Lastly try to match of major version only..
+        // Lastly try to match of major version only.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version.getMajor() ==
@@ -192,7 +201,7 @@
         }
       }
     } else if (build) {
-      // No version, just a build number, search for the first one that matches
+      // No version, just a build number, return the first one that matches.
       for (i = 0; i < num_sdk_infos; ++i)
         if (check_sdk_info[i])
           return &m_sdk_directory_infos[i];
Index: lldb/test/API/macosx/rosetta/Makefile
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/rosetta/Makefile
@@ -0,0 +1,4 @@
+C_SOURCES := main.c
+override ARCH = x86_64
+
+include Makefile.rules
Index: lldb/test/API/macosx/rosetta/TestRosetta.py
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/rosetta/TestRosetta.py
@@ -0,0 +1,36 @@
+import lldb
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+
+
+def apple_silicon(test):
+    return platform.system() == 'Darwin' and test.getArchitecture() in [
+        'arm64', 'arm64e'
+    ]
+
+
+class TestRosetta(TestBase):
+
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def no_apple_silicon(self):
+        if not apple_silicon(self):
+            return "Rosetta requires Apple Silicon"
+        return None
+
+    @skipTestIfFn(no_apple_silicon)
+    def test_rosetta(self):
+        """There can be many tests in a test case - describe this test here."""
+        self.build()
+        self.main_source_file = lldb.SBFileSpec("main.c")
+
+        broadcaster = self.dbg.GetBroadcaster()
+        listener = lldbutil.start_listening_from(
+            broadcaster, lldb.SBDebugger.eBroadcastBitWarning)
+
+        target, process, thread, bkpt = lldbutil.run_to_source_breakpoint(
+            self, "Set a breakpoint here", self.main_source_file)
+
+        event = lldb.SBEvent()
+        self.assertFalse(listener.GetNextEvent(event))
Index: lldb/test/API/macosx/rosetta/main.c
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/rosetta/main.c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main() {
+  int i = 0; // Set a breakpoint here
+  return i;
+}