diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
@@ -538,6 +538,7 @@
   ExternalTypeModuleMap m_external_type_modules;
   std::unique_ptr<lldb_private::DWARFIndex> m_index;
   bool m_fetched_external_modules : 1;
+  bool m_dwo_warning_issued : 1;
   lldb_private::LazyBool m_supports_DW_AT_APPLE_objc_complete_type;
 
   typedef std::set<DIERef> DIERefSet;
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -412,7 +412,7 @@
                                   // contain the .o file index/ID
       m_debug_map_module_wp(), m_debug_map_symfile(nullptr),
       m_context(m_objfile_sp->GetModule()->GetSectionList(), dwo_section_list),
-      m_fetched_external_modules(false),
+      m_fetched_external_modules(false), m_dwo_warning_issued(false),
       m_supports_DW_AT_APPLE_objc_complete_type(eLazyBoolCalculate) {}
 
 SymbolFileDWARF::~SymbolFileDWARF() = default;
@@ -1745,8 +1745,15 @@
     dwo_file.AppendPathComponent(dwo_name);
   }
 
-  if (!FileSystem::Instance().Exists(dwo_file))
+  if (!FileSystem::Instance().Exists(dwo_file)) {
+    if (!m_dwo_warning_issued) {
+      m_dwo_warning_issued = true;
+      GetObjectFile()->GetModule()->ReportWarning(
+          "unable to locate separate debug file (dwo, dwp). Debugging will be "
+          "degraded.");
+    }
     return nullptr;
+  }
 
   const lldb::offset_t file_offset = 0;
   DataBufferSP dwo_file_data_sp;
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/dwo-not-found-warning.cpp b/lldb/test/Shell/SymbolFile/DWARF/x86/dwo-not-found-warning.cpp
new file mode 100644
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/dwo-not-found-warning.cpp
@@ -0,0 +1,7 @@
+// RUN: %clang --target=x86_64-pc-linux -g -gsplit-dwarf -c %s -o %t.o
+// RUN: rm %t.dwo
+// RUN: %lldb %t.o -o "br set -n main" -o exit 2>&1 | FileCheck %s
+
+// CHECK: warning: {{.*}} unable to locate separate debug file (dwo, dwp). Debugging will be degraded.
+
+int main() { return 47; }