Warn and be ok with symbol services failing.

src/xenia/cpu/processor.cc

@@ -140,10 +140,15 @@ bool Processor::Setup() {
   frontend_ = std::move(frontend);
 
   // Stack walker is used when profiling, debugging, and dumping.
+  // Note that creation may fail, in which case we'll have to disable those
+  // features.
   stack_walker_ = StackWalker::Create(backend_->code_cache());
   if (!stack_walker_) {
-    XELOGE("Unable to create stack walker");
-    return false;
+    // TODO(benvanik): disable features.
+    if (FLAGS_debug) {
+      XELOGW("Disabling --debug due to lack of stack walker");
+      FLAGS_debug = false;
+    }
   }
 
   // Open the trace data path, if requested.

src/xenia/cpu/stack_walker.h

@@ -58,6 +58,7 @@ struct StackFrame {
 class StackWalker {
  public:
   // Creates a stack walker. Only one should exist within a process.
+  // May fail if another process has mucked with ours (like RenderDoc).
   static std::unique_ptr<StackWalker> Create(backend::CodeCache* code_cache);
 
   // Dumps all thread stacks to the log.

src/xenia/cpu/stack_walker_win.cc

@@ -106,7 +106,7 @@ bool InitializeStackWalker() {
   options |= SYMOPT_FAIL_CRITICAL_ERRORS;
   sym_set_options_(options);
   if (!sym_initialize_(GetCurrentProcess(), nullptr, TRUE)) {
-    XELOGE("Unable to initialize symbol services");
+    XELOGE("Unable to initialize symbol services - already in use?");
     return false;
   }
 
@@ -311,7 +311,7 @@ std::unique_ptr<StackWalker> StackWalker::Create(
     backend::CodeCache* code_cache) {
   auto stack_walker = std::make_unique<Win32StackWalker>(code_cache);
   if (!stack_walker->Initialize()) {
-    XELOGE("Unable to initialize stack walker");
+    XELOGE("Unable to initialize stack walker: debug/save states disabled");
     return nullptr;
   }
   return std::unique_ptr<StackWalker>(stack_walker.release());