Merge pull request #3572 from canonical/fix_info_failure_on_old_ubuntu

[daemon] fix the multipass info after multipass launch failure

src/daemon/runtime_instance_info_helper.cpp

@@ -94,7 +94,10 @@ void mp::RuntimeInstanceInfoHelper::populate_runtime_info(mp::VirtualMachine& vm
     info->set_disk_total(results[Keys::disk_total_key].as<std::string>());
     info->set_cpu_count(results[Keys::cpus_key].as<std::string>());
     instance_info->set_cpu_times(results[Keys::cpu_times_key].as<std::string>());
-    instance_info->set_uptime(results[Keys::uptime_key].as<std::string>());
+    // Some older versions Ubuntu might return nothing from "uptime -p" command, which makes the
+    // results[Keys::uptime_key] null, so IsNull check is necessary here
+    instance_info->set_uptime(results[Keys::uptime_key].IsNull() ? "0 minutes"
+                                                                 : results[Keys::uptime_key].as<std::string>());
 
     auto current_release = results[Keys::current_release_key].as<std::string>();
     instance_info->set_current_release(!current_release.empty() ? current_release : original_release);