improve UI visibility of System/Logger

file/luajit_node.cc

@@ -133,9 +133,6 @@ class Node::Lambda final : public nf7::Node::Lambda,
     f_->Build().
         ThenIf(self, [this, in](auto& func) mutable {
           if (f_) StartThread(in, func);
-        }).
-        Catch<nf7::Exception>([log = log_](auto&) {
-          log->Warn("skips execution because of build failure");
         });
   } catch (nf7::ExpiredException&) {
   }

file/system_logger.cc

@@ -331,9 +331,31 @@ void Logger::LogView() noexcept {
       }
       // msg column
       if (ImGui::TableNextColumn()) {
-        ImGui::TextUnformatted(row.msg.c_str());
+        auto len = row.msg.find('\n');
+        if (len == std::string::npos) {
+          len = row.msg.size();
+        }
+        const char* str = row.msg.c_str();
+        ImGui::TextUnformatted(str, str+len);
         if (ImGui::IsItemHovered()) {
-          ImGui::SetTooltip(row.msg.c_str());
+          ImGui::BeginTooltip();
+          ImGui::TextUnformatted(row.msg.c_str());
+          if (row.ex) {
+            ImGui::Spacing();
+            ImGui::TextUnformatted("exception stack:");
+            for (auto ptr = row.ex; ptr;)
+            try {
+              ImGui::Bullet();
+              std::rethrow_exception(ptr);
+            } catch (Exception& e) {
+              ImGui::TextUnformatted(e.msg().c_str());
+              ptr = e.reason();
+            } catch (std::exception& e) {
+              ImGui::TextUnformatted(e.what());
+              ptr = nullptr;
+            }
+          }
+          ImGui::EndTooltip();
         }
       }
       // path column