diff --git a/pkg/backend/redis/queue.go b/pkg/backend/redis/queue.go
index 44ea134..02a1c58 100644
--- a/pkg/backend/redis/queue.go
+++ b/pkg/backend/redis/queue.go
@@ -20,6 +20,7 @@ package redis
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"reflect"
 	"time"
 
@@ -271,8 +272,10 @@ func (b *Backend) ensureQueueExistsByUID(rds redis.Cmdable, uid string) (*taskqu
 	rawQueue, err := rds.Get(b.queueKey(uid)).Result()
 	switch {
 	case err == redis.Nil:
+		b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("GET %s", b.queueKey(uid))).Msg("debug-next-task")
 		return nil, iface.TaskQueueNotFound
 	case err != nil:
+		b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("GET %s", b.queueKey(uid))).Msg("debug-next-task")
 		return nil, err
 	}
 
diff --git a/pkg/backend/redis/task.go b/pkg/backend/redis/task.go
index bc46448..d6ae9c5 100644
--- a/pkg/backend/redis/task.go
+++ b/pkg/backend/redis/task.go
@@ -398,9 +398,11 @@ func (b *Backend) NextTask(ctx context.Context, queueUID, workerUID uuid.UUID) (
 		toPop := false
 		numWorkerPending, err := tx.LLen(workerPendingQueueKey).Result()
 		if err == redis.Nil {
+			b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("LLEN %s", workerPendingQueueKey)).Msg("debug-next-task")
 			toPop = true
 		}
 		if err != nil {
+			b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("LLEN %s", workerPendingQueueKey)).Msg("debug-next-task")
 			return err
 		}
 		if numWorkerPending == 0 {
@@ -413,11 +415,13 @@ func (b *Backend) NextTask(ctx context.Context, queueUID, workerUID uuid.UUID) (
 			return nil
 		})
 		if err == redis.Nil {
+			b.Logger.Error().Stack().Err(err).Msg("debug-next-task: this should not happen.")
 			return backoff.Permanent(iface.TaskQueueEmptyError)
 		}
 		return err
 	}, queueKey, workerPendingQueueKey)
 	if err != nil {
+		b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("MULTI; RPOPLPUSH %s %s; EXEC", pendingQueueKey, workerPendingQueueKey)).Msg("debug-next-task")
 		return nil, err
 	}
 
@@ -454,9 +458,11 @@ func (b *Backend) NextTask(ctx context.Context, queueUID, workerUID uuid.UUID) (
 			// peak worker pending queue
 			taskUIDs, err := tx.LRange(workerPendingQueueKey, -1, -1).Result()
 			if err == redis.Nil {
+				b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("LRANGE %s -1 -1", workerPendingQueueKey)).Msg("debug-next-task")
 				return backoff.Permanent(iface.TaskQueueEmptyError)
 			}
 			if err != nil {
+				b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("LRANGE %s -1 -1", workerPendingQueueKey)).Msg("debug-next-task")
 				return err
 			}
 			if len(taskUIDs) == 0 {
@@ -466,6 +472,7 @@ func (b *Backend) NextTask(ctx context.Context, queueUID, workerUID uuid.UUID) (
 			// get Task and transit to Received
 			raw, err := tx.Get(b.taskKey(queue.UID.String(), taskUIDs[0])).Result()
 			if err != nil {
+				b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("Get %s", b.taskKey(queue.UID.String(), taskUIDs[0]))).Msg("debug-next-task")
 				return err
 			}
 			t = &task.Task{}
@@ -504,6 +511,7 @@ func (b *Backend) NextTask(ctx context.Context, queueUID, workerUID uuid.UUID) (
 		workerPendingQueueKey, workerTasksKey,
 	)
 	if err != nil {
+		b.Logger.Error().Stack().Err(err).Str("redis cmd", fmt.Sprintf("MULTI; RPOP %s; SADD %s %s; Set %s <marshaled> -1; EXEC", workerPendingQueueKey, workerTasksKey, t.UID, b.taskKey(queue.UID.String(), t.UID))).Msg("debug-next-task")
 		return nil, err
 	}
 	return t, nil