detect oom in tasks correctly

src/tasks.js

@@ -171,9 +171,8 @@ function startTask(id, options, callback) {
         if (!gTasks[id]) return; // ignore task exit since we are shutting down. see stopAllTasks
 
         const code = sudoError ? sudoError.code : 0;
-        const signal = sudoError ? sudoError.signal : 0;
 
-        debug(`startTask: ${id} completed with code ${code} and signal ${signal}`);
+        debug(`startTask: ${id} completed with code ${code}`);
 
         if (options.timeout) clearTimeout(killTimerId);
 
@@ -186,9 +185,9 @@ function startTask(id, options, callback) {
                     message: `Task ${id} ${timedOut ? 'timed out' : 'stopped'}` ,
                     code: timedOut ? exports.ETIMEOUT : exports.ESTOPPED
                 };
-            } else { // task crashed
+            } else { // task crashed. for code, maybe we can check systemctl show box-task-1707 -p ExecMainStatus
                 taskError = {
-                    message: signal === 9 ? `Task ${id} crashed as it ran out of memory` : `Task ${id} crashed with code ${code} and signal ${signal}`,
+                    message: code === 2 ? `Task ${id} crashed as it ran out of memory` : `Task ${id} crashed with code ${code}`,
                     code: exports.ECRASHED
                 };
             }