chore: address compiler warnings

engine/controllers/process_manager.cc

@@ -9,7 +9,13 @@ void ProcessManager::destroy(
     std::function<void(const HttpResponsePtr&)>&& callback) {
   auto loaded_engines = engine_service_->GetSupportedEngineNames();
   for (const auto& engine : loaded_engines.value()) {
-    engine_service_->UnloadEngine(engine);
+    auto result = engine_service_->UnloadEngine(engine);
+    if (!result) {
+      // Handle the error if any.
+      // Log the Error
+      LOG_ERROR << "Error unloading engine: " << result.error();
+      continue;
+    }
   }
   app().quit();
   Json::Value ret;

engine/services/hardware_service.cc

@@ -323,7 +323,14 @@ void HardwareService::UpdateHardwareInfos() {
   };
   for (auto const& he : b.value()) {
     if (!exists(he.uuid)) {
-      db_service_->DeleteHardwareEntry(he.uuid);
+      auto result = db_service_->DeleteHardwareEntry(he.uuid);
+      if (!result) {
+        // Handle the error if any.
+        // Log the Error
+        LOG_ERROR << "Error deleting hardware entry " << he.uuid << ": "
+                  << result.error();
+        continue;
+      }
     }
   }
 

engine/utils/command_executor.h

@@ -20,7 +20,7 @@ class CommandExecutor {
     if (!pipe) {
       throw std::runtime_error("popen() failed!");
     }
-    m_pipe = std::unique_ptr<FILE, decltype(&PCLOSE)>(pipe, PCLOSE);
+    m_pipe = std::unique_ptr<FILE, void (*)(FILE*)>(pipe, [](FILE* file) { if (file) { PCLOSE(file); } });
   }
 
   CommandExecutor(const CommandExecutor&) = delete;
@@ -46,5 +46,5 @@ class CommandExecutor {
   }
 
  private:
-  std::unique_ptr<FILE, decltype(&PCLOSE)> m_pipe{nullptr, PCLOSE};
+  std::unique_ptr<FILE, void (*)(FILE*)> m_pipe{nullptr, [](FILE* file) { if (file) { PCLOSE(file); } }};
 };