diff --git a/database/src/fs.rs b/database/src/fs.rs
index d87685c..210dcea 100644
--- a/database/src/fs.rs
+++ b/database/src/fs.rs
@@ -837,24 +837,25 @@ mod tests {
             .unwrap()
             .0;
 
-        assert!(db.merge(k1).unwrap().into_tpk_status().email_status.len() > 0);
-        assert!(
-            db.merge(k2.clone())
-                .unwrap()
-                .into_tpk_status()
-                .email_status
-                .len()
-                > 0
-        );
+        assert!(!db
+            .merge(k1)
+            .unwrap()
+            .into_tpk_status()
+            .email_status
+            .is_empty());
+        assert!(!db
+            .merge(k2.clone())
+            .unwrap()
+            .into_tpk_status()
+            .email_status
+            .is_empty());
         assert!(!db.merge(k2).unwrap().into_tpk_status().email_status.len() > 0);
-        assert!(
-            db.merge(k3.clone())
-                .unwrap()
-                .into_tpk_status()
-                .email_status
-                .len()
-                > 0
-        );
+        assert!(!db
+            .merge(k3.clone())
+            .unwrap()
+            .into_tpk_status()
+            .email_status
+            .is_empty());
         assert!(
             !db.merge(k3.clone())
                 .unwrap()
diff --git a/database/src/test.rs b/database/src/test.rs
index c54c5eb..1720382 100644
--- a/database/src/test.rs
+++ b/database/src/test.rs
@@ -100,7 +100,7 @@ pub fn test_uid_verification(db: &mut impl Database, log_path: &Path) {
         let raw = db.by_fpr(&fpr).unwrap();
         let key = Cert::from_bytes(raw.as_bytes()).unwrap();
 
-        assert!(key.userids().skip(1).next().is_none());
+        assert!(key.userids().nth(1).is_none());
         assert!(key.user_attributes().next().is_none());
         assert!(key.keys().subkeys().next().is_none());
 
@@ -128,7 +128,7 @@ pub fn test_uid_verification(db: &mut impl Database, log_path: &Path) {
         let raw = db.by_fpr(&fpr).unwrap();
         let key = Cert::from_bytes(raw.as_bytes()).unwrap();
 
-        assert!(key.userids().skip(1).next().is_none());
+        assert!(key.userids().nth(1).is_none());
         assert!(key.user_attributes().next().is_none());
         assert!(key.keys().subkeys().next().is_none());
 
@@ -161,7 +161,7 @@ pub fn test_uid_verification(db: &mut impl Database, log_path: &Path) {
         assert!(key.keys().subkeys().next().is_none());
 
         let myuid1 = key.userids().next().unwrap().userid().clone();
-        let myuid2 = key.userids().skip(1).next().unwrap().userid().clone();
+        let myuid2 = key.userids().nth(1).unwrap().userid().clone();
 
         assert_eq!(db.by_email(&email1).unwrap(), raw);
         assert_eq!(db.by_email(&email2).unwrap(), raw);
@@ -208,7 +208,7 @@ pub fn test_uid_verification(db: &mut impl Database, log_path: &Path) {
         assert!(key.keys().subkeys().next().is_none());
 
         let myuid1 = key.userids().next().unwrap().userid().clone();
-        let myuid2 = key.userids().skip(1).next().unwrap().userid().clone();
+        let myuid2 = key.userids().nth(1).unwrap().userid().clone();
 
         assert_eq!(db.by_email(&email1).unwrap(), raw);
         assert_eq!(db.by_email(&email2).unwrap(), raw);
@@ -1331,7 +1331,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
 
     // Have Alice certify the binding between "bob@bar.com" and
     // Bob's key.
-    let alice_certifies_bob = bob.userids().nth(0).unwrap().userid().bind(
+    let alice_certifies_bob = bob.userids().next().unwrap().userid().bind(
         &mut alice_signer,
         &bob,
         SignatureBuilder::new(SignatureType::GenericCertification)
@@ -1361,7 +1361,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     check_log_entry(log_path, &bobs_fp);
     let bob_ = Cert::from_bytes(&db.by_fpr(&bobs_fp).unwrap())?;
     assert_eq!(bob_.bad_signatures().count(), 0);
-    assert_eq!(bob_.userids().nth(0).unwrap().certifications().count(), 0);
+    assert_eq!(bob_.userids().next().unwrap().certifications().count(), 0);
 
     // Add the attestation, merge into the db, check that the
     // certification is now included.
@@ -1370,11 +1370,11 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     check_log_entry(log_path, &bobs_fp);
     let bob_ = Cert::from_bytes(&db.by_fpr(&bobs_fp).unwrap())?;
     assert_eq!(bob_.bad_signatures().count(), 0);
-    assert_eq!(bob_.userids().nth(0).unwrap().certifications().count(), 1);
+    assert_eq!(bob_.userids().next().unwrap().certifications().count(), 1);
     assert_eq!(
         bob_.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attestation_key_signatures()
             .count(),
@@ -1383,7 +1383,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     assert_eq!(
         bob_.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attested_certifications()
             .count(),
@@ -1396,7 +1396,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     check_log_entry(log_path, &bobs_fp);
     let bob_ = Cert::from_bytes(&db.by_fpr(&bobs_fp).unwrap())?;
     assert_eq!(bob_.bad_signatures().count(), 0);
-    assert_eq!(bob_.userids().nth(0).unwrap().certifications().count(), 1);
+    assert_eq!(bob_.userids().next().unwrap().certifications().count(), 1);
 
     // Finally, withdraw consent by overriding the attestation, merge
     // into the db, check that the certification is now gone.
@@ -1409,11 +1409,11 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     let clear_attestation = attestations[0].clone();
 
     let bob = bob.insert_packets(vec![clear_attestation])?;
-    assert_eq!(bob.userids().nth(0).unwrap().certifications().count(), 1);
+    assert_eq!(bob.userids().next().unwrap().certifications().count(), 1);
     assert_eq!(
         bob.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attestation_key_signatures()
             .count(),
@@ -1422,7 +1422,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     assert_eq!(
         bob.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attested_certifications()
             .count(),
@@ -1433,11 +1433,11 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     check_log_entry(log_path, &bobs_fp);
     let bob_ = Cert::from_bytes(&db.by_fpr(&bobs_fp).unwrap())?;
     assert_eq!(bob_.bad_signatures().count(), 0);
-    assert_eq!(bob_.userids().nth(0).unwrap().certifications().count(), 0);
+    assert_eq!(bob_.userids().next().unwrap().certifications().count(), 0);
     assert_eq!(
         bob_.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attestation_key_signatures()
             .count(),
@@ -1446,7 +1446,7 @@ pub fn attested_key_signatures(db: &mut impl Database, log_path: &Path) -> Resul
     assert_eq!(
         bob_.with_policy(&POLICY, None)?
             .userids()
-            .nth(0)
+            .next()
             .unwrap()
             .attested_certifications()
             .count(),
diff --git a/hagridctl/src/import.rs b/hagridctl/src/import.rs
index 9d0de3f..2d5c116 100644
--- a/hagridctl/src/import.rs
+++ b/hagridctl/src/import.rs
@@ -151,20 +151,14 @@ fn import_from_file(db: &KeyDatabase, input: &Path, multi_progress: &MultiProgre
 
     read_file_to_tpks(input_reader, &mut |acc| {
         let primary_key = acc[0].clone();
-        let result = import_key(&db, acc);
+        let result = import_key(db, acc);
         if let Err(ref e) = result {
             let key_fpr = match primary_key {
                 Packet::PublicKey(key) => key.fingerprint().to_hex(),
                 Packet::SecretKey(key) => key.fingerprint().to_hex(),
                 _ => "Unknown".to_owned(),
             };
-            let error = format!(
-                "{}:{:05}:{}: {}",
-                filename,
-                stats.count_total,
-                key_fpr,
-                e.to_string()
-            );
+            let error = format!("{}:{:05}:{}: {}", filename, stats.count_total, key_fpr, e);
             progress_bar.println(error);
         }
         stats.update(result);
@@ -176,7 +170,7 @@ fn import_from_file(db: &KeyDatabase, input: &Path, multi_progress: &MultiProgre
 
 fn read_file_to_tpks(
     reader: impl Read + Send + Sync,
-    callback: &mut impl FnMut(Vec<Packet>) -> (),
+    callback: &mut impl FnMut(Vec<Packet>),
 ) -> Result<()> {
     let mut ppr = PacketParser::from_reader(reader)?;
     let mut acc = Vec::new();
diff --git a/hagridctl/src/regenerate.rs b/hagridctl/src/regenerate.rs
index e995a99..e3d4f79 100644
--- a/hagridctl/src/regenerate.rs
+++ b/hagridctl/src/regenerate.rs
@@ -46,7 +46,7 @@ impl<'a> RegenerateStats<'a> {
         }
         match result {
             Err(e) => {
-                self.progress.println(format!("{}: {}", fpr, e.to_string()));
+                self.progress.println(format!("{}: {}", fpr, e));
                 self.count_err += 1;
             }
             Ok(RegenerateResult::Updated) => self.count_updated += 1,