diff --git a/src/lib/shell/assignments.rs b/src/lib/shell/assignments.rs
index 7c321f7143a20c571ac9f0b85f05390ca98e0e6a..d532ffce12f1d643db35386e081fcba6eab7d9ec 100644
--- a/src/lib/shell/assignments.rs
+++ b/src/lib/shell/assignments.rs
@@ -440,8 +440,10 @@ impl VariableStore for Shell {
         for action in actions_step2 {
             match action {
                 Ok(Action::UpdateArray(key, operator, ..)) => {
-                    if operator == Operator::OptionalEqual && self.variables.get_ref(key.name).is_some() {
-                            continue;
+                    if operator == Operator::OptionalEqual
+                        && self.variables.get_ref(key.name).is_some()
+                    {
+                        continue;
                     }
                     match collected.remove(key.name) {
                         hmap @ Some(VariableType::HashMap(_)) => {
@@ -528,7 +530,9 @@ impl VariableStore for Shell {
                     }
                 }
                 Ok(Action::UpdateString(key, operator, ..)) => {
-                    if operator == Operator::OptionalEqual && self.variables.get_ref(key.name).is_some() {
+                    if operator == Operator::OptionalEqual
+                        && self.variables.get_ref(key.name).is_some()
+                    {
                         continue;
                     }
                     match collected.remove(key.name) {
diff --git a/src/lib/shell/mod.rs b/src/lib/shell/mod.rs
index 8c49e96318c79d9fb5eca0ed6150d710db6584d2..a098e672b1cc2ae9921c849e313f11ce8fff8cfb 100644
--- a/src/lib/shell/mod.rs
+++ b/src/lib/shell/mod.rs
@@ -120,6 +120,7 @@ pub struct Shell {
     ignore_setting: IgnoreSetting,
 }
 
+#[derive(Default)]
 pub struct ShellBuilder;
 
 impl ShellBuilder {
diff --git a/src/lib/shell/pipe_exec/mod.rs b/src/lib/shell/pipe_exec/mod.rs
index aefab2f9195f91a798af4b40f3cf7678d4348039..efe71b4295763cae42d0eeb7c330f2ec7357c911 100644
--- a/src/lib/shell/pipe_exec/mod.rs
+++ b/src/lib/shell/pipe_exec/mod.rs
@@ -815,9 +815,7 @@ pub(crate) fn pipe(
 
                     ext_stdio_pipes = None;
 
-                    if set_process_group(&mut pgid, current_pid)
-                        && foreground
-                        && !shell.is_library
+                    if set_process_group(&mut pgid, current_pid) && foreground && !shell.is_library
                     {
                         let _ = sys::tcsetpgrp(0, pgid);
                     }
diff --git a/src/lib/shell/variables/mod.rs b/src/lib/shell/variables/mod.rs
index 8b7c125a169c34b0e934bf0dbc9f9d400b626121..5b8d852685b3fab4ed4afc0d5dbf0fe9dfe34a97 100644
--- a/src/lib/shell/variables/mod.rs
+++ b/src/lib/shell/variables/mod.rs
@@ -127,25 +127,19 @@ impl fmt::Display for VariableType {
             VariableType::Alias(ref alias) => write!(f, "{}", **alias),
             VariableType::Array(ref array) => write!(f, "{}", array.join(" ")),
             VariableType::HashMap(ref map) => {
-                let mut format =
-                    map.into_iter()
-                        .fold(String::new(), |mut format, (_, var_type)| {
-                            format.push_str(&format!("{}", var_type));
-                            format.push(' ');
-                            format
-                        });
-                format.pop();
+                let format = map
+                    .iter()
+                    .map(|(_, var_type)| format!("{}", var_type))
+                    .collect::<Vec<_>>()
+                    .join(" ");
                 write!(f, "{}", format)
             }
             VariableType::BTreeMap(ref map) => {
-                let mut format =
-                    map.iter()
-                        .fold(String::new(), |mut format, (_, var_type)| {
-                            format.push_str(&format!("{}", var_type));
-                            format.push(' ');
-                            format
-                        });
-                format.pop();
+                let format = map
+                    .iter()
+                    .map(|(_, var_type)| format!("{}", var_type))
+                    .collect::<Vec<_>>()
+                    .join(" ");
                 write!(f, "{}", format)
             }
             _ => write!(f, ""),