Index: lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
===================================================================
--- lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
+++ lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
@@ -9,6 +9,7 @@
 #ifndef liblldb_Lua_h_
 #define liblldb_Lua_h_
 
+#include "lldb/lldb-types.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Error.h"
 
@@ -35,6 +36,7 @@
     luaL_openlibs(m_lua_state);
   }
 
+  llvm::Error EnterSession(lldb::user_id_t debugger_id);
   llvm::Error Run(llvm::StringRef buffer);
 
 private:
Index: lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
===================================================================
--- lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
+++ lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
@@ -10,6 +10,7 @@
 #include "llvm/Support/FormatVariadic.h"
 
 using namespace lldb_private;
+using namespace lldb;
 
 llvm::Error Lua::Run(llvm::StringRef buffer) {
   std::lock_guard<std::mutex> lock(m_mutex);
@@ -26,3 +27,13 @@
   lua_pop(m_lua_state, 1);
   return e;
 }
+
+llvm::Error Lua::EnterSession(user_id_t debugger_id) {
+  const char *fmt_str =
+      "lldb.debugger = lldb.SBDebugger.FindDebuggerWithID({0}); "
+      "lldb.target = lldb.debugger:GetSelectedTarget(); "
+      "lldb.process = lldb.target:GetProcess(); "
+      "lldb.thread = lldb.process:GetSelectedThread(); "
+      "lldb.frame = lldb.thread:GetSelectedFrame()";
+  return Run(llvm::formatv(fmt_str, debugger_id).str());
+}
Index: lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
===================================================================
--- lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
+++ lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
@@ -42,7 +42,9 @@
 
 ScriptInterpreterLua::ScriptInterpreterLua(Debugger &debugger)
     : ScriptInterpreter(debugger, eScriptLanguageLua),
-      m_lua(std::make_unique<Lua>()) {}
+      m_lua(std::make_unique<Lua>()) {
+  llvm::cantFail(GetLua().EnterSession(debugger.GetID()));
+}
 
 ScriptInterpreterLua::~ScriptInterpreterLua() {}
 
Index: lldb/test/Shell/ScriptInterpreter/Lua/Inputs/independent_state.in
===================================================================
--- /dev/null
+++ lldb/test/Shell/ScriptInterpreter/Lua/Inputs/independent_state.in
@@ -0,0 +1,6 @@
+script foobar = 40 + 7
+script print(foobar)
+script d = lldb.SBDebugger.Create()
+script d:HandleCommand("script foobar = 40 + 2")
+script print(foobar)
+script d:HandleCommand("script print(foobar)")
Index: lldb/test/Shell/ScriptInterpreter/Lua/convenience_variables.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/ScriptInterpreter/Lua/convenience_variables.test
@@ -0,0 +1,17 @@
+# REQUIRES: lua
+#
+# This tests that the convenience variables are not nil. Given that there is no
+# target we only expect the debugger to be valid.
+#
+# RUN: cat %s | %lldb --script-language lua 2>&1 | FileCheck %s
+script
+print(string.format("lldb.debugger is valid: %s", lldb.debugger:IsValid()))
+print(string.format("lldb.target is valid: %s", lldb.target:IsValid()))
+print(string.format("lldb.process is valid: %s", lldb.process:IsValid()))
+print(string.format("lldb.thread is valid: %s", lldb.thread:IsValid()))
+print(string.format("lldb.frame is valid: %s", lldb.frame:IsValid()))
+# CHECK: debugger is valid: true
+# CHECK: target is valid: false
+# CHECK: process is valid: false
+# CHECK: thread is valid: false
+# CHECK: frame is valid: false
Index: lldb/test/Shell/ScriptInterpreter/Lua/independent_state.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/ScriptInterpreter/Lua/independent_state.test
@@ -0,0 +1,6 @@
+# REQUIRES: lua
+#
+# RUN:  %lldb --script-language lua -s %S/Inputs/independent_state.in 2>&1 | FileCheck %s
+# CHECK: 47
+# CHECK: 47
+# CHECK: 42