add string representation to SessionResult

llarp/router/i_outbound_session_maker.hpp

@@ -20,6 +20,25 @@ namespace llarp
     NoLink
   };
 
+  inline std::ostream&
+  operator<<(std::ostream& out, const SessionResult& st)
+  {
+    switch (st)
+    {
+      case SessionResult::Establish:
+        return out << "success";
+      case SessionResult::Timeout:
+        return out << "timeout";
+      case SessionResult::NoLink:
+        return out << "no link";
+      case SessionResult::InvalidRouter:
+        return out << "invalid router";
+      case SessionResult::RouterNotFound:
+        return out << "not found";
+    }
+    return out;
+  }
+
   using RouterCallback = std::function<void(const RouterID&, const SessionResult)>;
 
   struct IOutboundSessionMaker

llarp/router/router.cpp

@@ -1220,7 +1220,8 @@ namespace llarp
                       router,
                       " (",
                       previous_fails + 1,
-                      " consecutive failures)");
+                      " consecutive failures) result=",
+                      result);
                 }
                 else
                 {