diff --git a/lldb/packages/Python/lldbsuite/test/decorators.py b/lldb/packages/Python/lldbsuite/test/decorators.py
--- a/lldb/packages/Python/lldbsuite/test/decorators.py
+++ b/lldb/packages/Python/lldbsuite/test/decorators.py
@@ -698,6 +698,17 @@
             archs),
         bugnumber)
 
+def skipUnlessAppleSilicon(func):
+    """Decorate the item to skip tests unless running on Apple Silicon."""
+    def not_apple_silicon(test):
+        if platform.system() != 'Darwin' or test.getArchitecture() not in [
+                'arm64', 'arm64e'
+        ]:
+            return "Test only runs on Apple Silicon"
+        return None
+
+    return skipTestIfFn(not_apple_silicon)(func)
+
 def skipUnlessSupportedTypeAttribute(attr):
     """Decorate the item to skip test unless Clang supports type __attribute__(attr)."""
     def compiler_doesnt_support_struct_attribute(self):
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp
+++ b/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];
diff --git a/lldb/test/API/macosx/rosetta/Makefile b/lldb/test/API/macosx/rosetta/Makefile
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/macosx/rosetta/Makefile
@@ -0,0 +1,4 @@
+C_SOURCES := main.c
+override ARCH = x86_64
+
+include Makefile.rules
diff --git a/lldb/test/API/macosx/rosetta/TestRosetta.py b/lldb/test/API/macosx/rosetta/TestRosetta.py
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/macosx/rosetta/TestRosetta.py
@@ -0,0 +1,55 @@
+import re
+import lldb
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+
+
+def get_os_version():
+    try:
+        os_version_str = subprocess.check_output(["sysctl", "kern.osversion"
+                                                  ]).decode('utf-8')
+    except subprocess.CalledProcessError:
+        return None
+    m = re.match(r'kern\.osversion: (\w+)', os_version_str)
+    if m:
+        return m.group(1)
+    return None
+
+
+def has_rosetta_shared_cache(os_version):
+    if not os_version:
+        return False
+    macos_device_support = os.path.join(os.path.expanduser("~"), 'Library',
+                                        'Developer', 'Xcode',
+                                        'macOS DeviceSupport')
+    for _, subdirs, _ in os.walk(macos_device_support):
+        for subdir in subdirs:
+            if os_version in subdir:
+                return True
+    return False
+
+
+class TestRosetta(TestBase):
+
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipUnlessAppleSilicon
+    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()
+        os_version = get_os_version()
+        if not has_rosetta_shared_cache(os_version):
+            self.assertTrue(listener.GetNextEvent(event))
+        else:
+            self.assertFalse(listener.GetNextEvent(event))
diff --git a/lldb/test/API/macosx/rosetta/main.c b/lldb/test/API/macosx/rosetta/main.c
new file mode 100644
--- /dev/null
+++ b/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;
+}