diff --git a/Dockerfile b/Dockerfile
index ffc4e254df..1bc7a0d49d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM rust:1.54-buster as builder
+FROM rust:1.57-buster as builder
 WORKDIR /app
 ADD . /app
 ENV PATH=$PATH:/root/.cargo/bin
diff --git a/src/db/mysql/batch.rs b/src/db/mysql/batch.rs
index 33d8ad6322..4719375f49 100644
--- a/src/db/mysql/batch.rs
+++ b/src/db/mysql/batch.rs
@@ -189,7 +189,6 @@ pub fn do_append(
     #[derive(Debug, QueryableByName)]
     #[table_name = "batch_upload_items"]
     struct ExistsResult {
-        user_id: i64,
         batch_id: i64,
         id: String,
     }
diff --git a/src/web/tags.rs b/src/web/tags.rs
index e1345c51fd..06bc9bcc33 100644
--- a/src/web/tags.rs
+++ b/src/web/tags.rs
@@ -18,21 +18,12 @@ use slog::{Key, Record, KV};
 
 use crate::server::user_agent::parse_user_agent;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct Tags {
     pub tags: HashMap<String, String>,
     pub extra: HashMap<String, String>,
 }
 
-impl Default for Tags {
-    fn default() -> Tags {
-        Tags {
-            tags: HashMap::new(),
-            extra: HashMap::new(),
-        }
-    }
-}
-
 impl Serialize for Tags {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where