dont log context canceled errors

A context canceled error will occur once the runc container has exited,
there is not need to log these errors.

Additionally, remove a printf that was accidentally committed.

executor/runcexecutor/monitor_stats.go

@@ -52,6 +52,9 @@ func (w *runcExecutor) monitorContainerStats(ctx context.Context, id string, sam
 
 		stats, err := w.runc.Stats(ctx, id)
 		if err != nil {
+			if errors.Is(err, context.Canceled) {
+				return
+			}
 			if numFailuresAllowed > 0 {
 				// allow the initial calls to runc.Stats to fail, for cases where the program didn't start within the initial
 				// sampleFrequency; this should only occur under heavy workloads

worker/base/worker.go

@@ -334,7 +334,6 @@ func (w *Worker) ResolveOp(v solver.Vertex, s frontend.FrontendLLBBridge, sm *se
 		case *pb.Op_Source:
 			return ops.NewSourceOp(v, op, baseOp.Platform, w.SourceManager, w.ParallelismSem, sm, w)
 		case *pb.Op_Exec:
-			fmt.Printf("Worker.ResolveOp called\n") // this just gets called once even with two client
 			return ops.NewExecOp(v, op, baseOp.Platform, w.CacheMgr, w.ParallelismSem, sm, w.WorkerOpt.Executor, w)
 		case *pb.Op_File:
 			return ops.NewFileOp(v, op, w.CacheMgr, w.ParallelismSem, w)