diff --git a/.azure/azure-pipelines.yml b/.azure/azure-pipelines.yml
index aa3cb8be6..fb58390aa 100644
--- a/.azure/azure-pipelines.yml
+++ b/.azure/azure-pipelines.yml
@@ -45,13 +45,13 @@ steps:
   - bash: RUSTFLAGS="-D warnings" cargo test --all --features=stable
     condition: eq(variables['style'], 'unflagged')
     displayName: Run tests
-  - bash: RUSTFLAGS="-D warnings" cargo clippy --all --features=stable
+  - bash: RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
     condition: eq(variables['style'], 'unflagged')
     displayName: Check clippy lints
   - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo test --all --features=stable
     condition: eq(variables['style'], 'canary')
     displayName: Run tests
-  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo clippy --all --features=stable
+  - bash: NUSHELL_ENABLE_ALL_FLAGS=1 RUSTFLAGS="-D warnings" cargo clippy --all --features=stable -- -D clippy::result_unwrap_used -D clippy::option_unwrap_used
     condition: eq(variables['style'], 'canary')
     displayName: Check clippy lints
   - bash: cargo fmt --all -- --check
diff --git a/Cargo.lock b/Cargo.lock
index 30d3256bb..d3f6d84c5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1817,6 +1817,15 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae91b68aebc4ddb91978b11a1b02ddd8602a05ec19002801c5666000e05e0f83"
 
+[[package]]
+name = "lock_api"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e57b3997725d2b60dbec1297f6c2e2957cc383db1cebd6be812163f969c7d586"
+dependencies = [
+ "scopeguard",
+]
+
 [[package]]
 name = "log"
 version = "0.4.8"
@@ -2170,6 +2179,7 @@ dependencies = [
  "num-bigint",
  "num-traits 0.2.10",
  "onig_sys",
+ "parking_lot",
  "pin-utils",
  "pretty-hex",
  "pretty_assertions",
@@ -2720,6 +2730,30 @@ dependencies = [
  "winapi 0.3.8",
 ]
 
+[[package]]
+name = "parking_lot"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "92e98c49ab0b7ce5b222f2cc9193fc4efe11c6d0bd4f648e374684a6857b1cfc"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7582838484df45743c8434fbff785e8edf260c28748353d44bc0da32e0ceabf1"
+dependencies = [
+ "cfg-if",
+ "cloudabi",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "winapi 0.3.8",
+]
+
 [[package]]
 name = "path-slash"
 version = "0.1.1"
diff --git a/Cargo.toml b/Cargo.toml
index 7b8229ba8..715b3b8a3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -123,6 +123,7 @@ umask = "0.1"
 futures-util = "0.3.1"
 termcolor = "1.0.5"
 natural = "0.3.0"
+parking_lot = "0.10.0"
 
 clipboard = {version = "0.5", optional = true }
 ptree = {version = "0.2" }
diff --git a/crates/nu-parser/src/parse/unit.rs b/crates/nu-parser/src/parse/unit.rs
index 1d695a73a..9b238eda4 100644
--- a/crates/nu-parser/src/parse/unit.rs
+++ b/crates/nu-parser/src/parse/unit.rs
@@ -34,8 +34,20 @@ impl PrettyDebug for Unit {
 
 fn convert_number_to_u64(number: &Number) -> u64 {
     match number {
-        Number::Int(big_int) => big_int.to_u64().unwrap(),
-        Number::Decimal(big_decimal) => big_decimal.to_u64().unwrap(),
+        Number::Int(big_int) => {
+            if let Some(x) = big_int.to_u64() {
+                x
+            } else {
+                unreachable!("Internal error: convert_number_to_u64 given incompatible number")
+            }
+        }
+        Number::Decimal(big_decimal) => {
+            if let Some(x) = big_decimal.to_u64() {
+                x
+            } else {
+                unreachable!("Internal error: convert_number_to_u64 given incompatible number")
+            }
+        }
     }
 }
 
diff --git a/crates/nu-protocol/src/type_shape.rs b/crates/nu-protocol/src/type_shape.rs
index a40fa825e..aa864416f 100644
--- a/crates/nu-protocol/src/type_shape.rs
+++ b/crates/nu-protocol/src/type_shape.rs
@@ -235,7 +235,7 @@ impl PrettyDebug for Type {
                 (b::kind("table") + b::space() + b::keyword("of")).group()
                     + b::space()
                     + (if group.len() == 1 {
-                        let (doc, _) = group.into_iter().nth(0).unwrap();
+                        let (doc, _) = group.into_iter().collect::<Vec<_>>()[0].clone();
                         DebugDocBuilder::from_doc(doc)
                     } else {
                         b::intersperse(
diff --git a/crates/nu-protocol/src/value/primitive.rs b/crates/nu-protocol/src/value/primitive.rs
index 171bd0059..8311ad13c 100644
--- a/crates/nu-protocol/src/value/primitive.rs
+++ b/crates/nu-protocol/src/value/primitive.rs
@@ -64,7 +64,11 @@ impl From<BigDecimal> for Primitive {
 
 impl From<f64> for Primitive {
     fn from(float: f64) -> Primitive {
-        Primitive::Decimal(BigDecimal::from_f64(float).unwrap())
+        if let Some(f) = BigDecimal::from_f64(float) {
+            Primitive::Decimal(f)
+        } else {
+            unreachable!("Internal error: protocol did not use f64-compatible decimal")
+        }
     }
 }
 
diff --git a/src/commands/autoview.rs b/src/commands/autoview.rs
index 0b728ea45..cfcf61ea6 100644
--- a/src/commands/autoview.rs
+++ b/src/commands/autoview.rs
@@ -100,13 +100,7 @@ pub fn autoview(
                                     let first = &input[0];
 
                                     let mut host = context.host.clone();
-                                    let mut host = match host.lock() {
-                                        Err(err) => {
-                                            errln!("Unexpected error acquiring host lock: {:?}", err);
-                                            return;
-                                        }
-                                        Ok(val) => val
-                                    };
+                                    let mut host = host.lock();
 
                                     crate::cli::print_err(first.value.expect_error(), &*host, &context.source);
                                     return;
diff --git a/src/commands/classified/external.rs b/src/commands/classified/external.rs
index 3b88467a5..f14fde52d 100644
--- a/src/commands/classified/external.rs
+++ b/src/commands/classified/external.rs
@@ -196,7 +196,13 @@ pub(crate) async fn run_external_command(
                 })?;
                 let file = futures::io::AllowStdIo::new(stdout);
                 let stream = Framed::new(file, LinesCodec {});
-                let stream = stream.map(move |line| line.unwrap().into_value(&name_tag));
+                let stream = stream.map(move |line| {
+                    if let Ok(line) = line {
+                        line.into_value(&name_tag)
+                    } else {
+                        panic!("Internal error: could not read lines of text from stdin")
+                    }
+                });
                 Ok(ClassifiedInputStream::from_input_stream(
                     stream.boxed() as BoxStream<'static, Value>
                 ))
diff --git a/src/commands/classified/internal.rs b/src/commands/classified/internal.rs
index e9ade195e..f2c37653f 100644
--- a/src/commands/classified/internal.rs
+++ b/src/commands/classified/internal.rs
@@ -124,7 +124,7 @@ pub(crate) async fn run_internal_command(
                     }
                     CommandAction::EnterShell(location) => {
                         context.shell_manager.insert_at_current(Box::new(
-                            FilesystemShell::with_location(location, context.registry().clone()).unwrap(),
+                            FilesystemShell::with_location(location, context.registry().clone()),
                         ))?;
                     }
                     CommandAction::PreviousShell => {
diff --git a/src/commands/command.rs b/src/commands/command.rs
index 184c3fee5..89d6db2e1 100644
--- a/src/commands/command.rs
+++ b/src/commands/command.rs
@@ -63,7 +63,7 @@ impl CallInfoExt for CallInfo {
 #[derive(Getters)]
 #[get = "pub(crate)"]
 pub struct CommandArgs {
-    pub host: Arc<Mutex<Box<dyn Host>>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
     pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: UnevaluatedCallInfo,
@@ -73,7 +73,7 @@ pub struct CommandArgs {
 #[derive(Getters, Clone)]
 #[get = "pub(crate)"]
 pub struct RawCommandArgs {
-    pub host: Arc<Mutex<Box<dyn Host>>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
     pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: UnevaluatedCallInfo,
@@ -219,7 +219,7 @@ pub struct RunnablePerItemContext {
 pub struct RunnableContext {
     pub input: InputStream,
     pub shell_manager: ShellManager,
-    pub host: Arc<Mutex<Box<dyn Host>>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
     pub source: Text,
     pub ctrl_c: Arc<AtomicBool>,
     pub commands: CommandRegistry,
@@ -286,7 +286,7 @@ impl Deref for EvaluatedWholeStreamCommandArgs {
 
 impl EvaluatedWholeStreamCommandArgs {
     pub fn new(
-        host: Arc<Mutex<dyn Host>>,
+        host: Arc<parking_lot::Mutex<dyn Host>>,
         ctrl_c: Arc<AtomicBool>,
         shell_manager: ShellManager,
         call_info: CallInfo,
@@ -335,7 +335,7 @@ impl Deref for EvaluatedFilterCommandArgs {
 
 impl EvaluatedFilterCommandArgs {
     pub fn new(
-        host: Arc<Mutex<dyn Host>>,
+        host: Arc<parking_lot::Mutex<dyn Host>>,
         ctrl_c: Arc<AtomicBool>,
         shell_manager: ShellManager,
         call_info: CallInfo,
@@ -354,7 +354,7 @@ impl EvaluatedFilterCommandArgs {
 #[derive(Getters, new)]
 #[get = "pub(crate)"]
 pub struct EvaluatedCommandArgs {
-    pub host: Arc<Mutex<dyn Host>>,
+    pub host: Arc<parking_lot::Mutex<dyn Host>>,
     pub ctrl_c: Arc<AtomicBool>,
     pub shell_manager: ShellManager,
     pub call_info: CallInfo,
@@ -555,7 +555,7 @@ impl WholeStreamCommand for FnFilterCommand {
             input,
         } = args;
 
-        let host: Arc<Mutex<dyn Host>> = host.clone();
+        let host: Arc<parking_lot::Mutex<dyn Host>> = host.clone();
         let registry: CommandRegistry = registry.clone();
         let func = self.func;
 
diff --git a/src/commands/from_yaml.rs b/src/commands/from_yaml.rs
index 915c9fa08..f8f329702 100644
--- a/src/commands/from_yaml.rs
+++ b/src/commands/from_yaml.rs
@@ -51,31 +51,49 @@ impl WholeStreamCommand for FromYML {
     }
 }
 
-fn convert_yaml_value_to_nu_value(v: &serde_yaml::Value, tag: impl Into<Tag>) -> Value {
+fn convert_yaml_value_to_nu_value(
+    v: &serde_yaml::Value,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
     let tag = tag.into();
 
-    match v {
+    Ok(match v {
         serde_yaml::Value::Bool(b) => UntaggedValue::boolean(*b).into_value(tag),
         serde_yaml::Value::Number(n) if n.is_i64() => {
-            UntaggedValue::int(n.as_i64().unwrap()).into_value(tag)
+            UntaggedValue::int(n.as_i64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Expected a compatible number",
+                    "expected a compatible number",
+                    &tag,
+                )
+            })?)
+            .into_value(tag)
         }
         serde_yaml::Value::Number(n) if n.is_f64() => {
-            UntaggedValue::decimal(n.as_f64().unwrap()).into_value(tag)
+            UntaggedValue::decimal(n.as_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Expected a compatible number",
+                    "expected a compatible number",
+                    &tag,
+                )
+            })?)
+            .into_value(tag)
         }
         serde_yaml::Value::String(s) => UntaggedValue::string(s).into_value(tag),
-        serde_yaml::Value::Sequence(a) => UntaggedValue::Table(
-            a.iter()
+        serde_yaml::Value::Sequence(a) => {
+            let result: Result<Vec<Value>, ShellError> = a
+                .iter()
                 .map(|x| convert_yaml_value_to_nu_value(x, &tag))
-                .collect(),
-        )
-        .into_value(tag),
+                .collect();
+            UntaggedValue::Table(result?).into_value(tag)
+        }
         serde_yaml::Value::Mapping(t) => {
             let mut collected = TaggedDictBuilder::new(&tag);
 
             for (k, v) in t.iter() {
                 match k {
                     serde_yaml::Value::String(k) => {
-                        collected.insert_value(k.clone(), convert_yaml_value_to_nu_value(v, &tag));
+                        collected.insert_value(k.clone(), convert_yaml_value_to_nu_value(v, &tag)?);
                     }
                     _ => unimplemented!("Unknown key type"),
                 }
@@ -85,12 +103,19 @@ fn convert_yaml_value_to_nu_value(v: &serde_yaml::Value, tag: impl Into<Tag>) ->
         }
         serde_yaml::Value::Null => UntaggedValue::Primitive(Primitive::Nothing).into_value(tag),
         x => unimplemented!("Unsupported yaml case: {:?}", x),
-    }
+    })
 }
 
-pub fn from_yaml_string_to_value(s: String, tag: impl Into<Tag>) -> serde_yaml::Result<Value> {
-    let v: serde_yaml::Value = serde_yaml::from_str(&s)?;
-    Ok(convert_yaml_value_to_nu_value(&v, tag))
+pub fn from_yaml_string_to_value(s: String, tag: impl Into<Tag>) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    let v: serde_yaml::Value = serde_yaml::from_str(&s).map_err(|x| {
+        ShellError::labeled_error(
+            format!("Could not load yaml: {}", x),
+            "could not load yaml from text",
+            &tag,
+        )
+    })?;
+    Ok(convert_yaml_value_to_nu_value(&v, tag)?)
 }
 
 fn from_yaml(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
diff --git a/src/commands/table.rs b/src/commands/table.rs
index 854967e24..01f1533f0 100644
--- a/src/commands/table.rs
+++ b/src/commands/table.rs
@@ -53,7 +53,7 @@ fn table(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream,
 
         let input: Vec<Value> = args.input.into_vec().await;
         if input.len() > 0 {
-            let mut host = host.lock().unwrap();
+            let mut host = host.lock();
             let view = TableView::from_list(&input, start_number);
 
             if let Some(view) = view {
diff --git a/src/commands/to_bson.rs b/src/commands/to_bson.rs
index 3b783b7af..478571e5a 100644
--- a/src/commands/to_bson.rs
+++ b/src/commands/to_bson.rs
@@ -49,7 +49,15 @@ pub fn value_to_bson_value(v: &Value) -> Result<Bson, ShellError> {
         UntaggedValue::Primitive(Primitive::Date(d)) => Bson::UtcDatetime(*d),
         UntaggedValue::Primitive(Primitive::EndOfStream) => Bson::Null,
         UntaggedValue::Primitive(Primitive::BeginningOfStream) => Bson::Null,
-        UntaggedValue::Primitive(Primitive::Decimal(d)) => Bson::FloatingPoint(d.to_f64().unwrap()),
+        UntaggedValue::Primitive(Primitive::Decimal(d)) => {
+            Bson::FloatingPoint(d.to_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Could not convert value to decimal",
+                    "could not convert to decimal",
+                    &v.tag,
+                )
+            })?)
+        }
         UntaggedValue::Primitive(Primitive::Int(i)) => {
             Bson::I64(i.tagged(&v.tag).coerce_into("converting to BSON")?)
         }
@@ -145,9 +153,9 @@ fn object_value_to_bson(o: &Dictionary) -> Result<Bson, ShellError> {
                     let bst = get_binary_subtype(tagged_binary_subtype_value);
                     let bin: Result<Vec<u8>, _> = tagged_bin_value.try_into();
 
-                    match bst {
-                        Err(_) => generic_object_value_to_bson(o),
-                        Ok(v) => Ok(Bson::Binary(v, bin.unwrap())),
+                    match (bin, bst) {
+                        (Ok(bin), Ok(v)) => Ok(Bson::Binary(v, bin)),
+                        _ => generic_object_value_to_bson(o),
                     }
                 }
                 _ => generic_object_value_to_bson(o),
diff --git a/src/commands/to_json.rs b/src/commands/to_json.rs
index e82455160..4293203a3 100644
--- a/src/commands/to_json.rs
+++ b/src/commands/to_json.rs
@@ -98,8 +98,17 @@ pub fn value_to_json_value(v: &Value) -> Result<serde_json::Value, ShellError> {
         UntaggedValue::Primitive(Primitive::Binary(b)) => serde_json::Value::Array(
             b.iter()
                 .map(|x| {
-                    serde_json::Value::Number(serde_json::Number::from_f64(*x as f64).unwrap())
+                    serde_json::Number::from_f64(*x as f64).ok_or_else(|| {
+                        ShellError::labeled_error(
+                            "Can not convert number from floating point",
+                            "can not convert to number",
+                            &v.tag,
+                        )
+                    })
                 })
+                .collect::<Result<Vec<serde_json::Number>, ShellError>>()?
+                .into_iter()
+                .map(serde_json::Value::Number)
                 .collect(),
         ),
         UntaggedValue::Row(o) => {
diff --git a/src/commands/to_yaml.rs b/src/commands/to_yaml.rs
index f0c1c0da1..19ea75f31 100644
--- a/src/commands/to_yaml.rs
+++ b/src/commands/to_yaml.rs
@@ -31,16 +31,34 @@ pub fn value_to_yaml_value(v: &Value) -> Result<serde_yaml::Value, ShellError> {
     Ok(match &v.value {
         UntaggedValue::Primitive(Primitive::Boolean(b)) => serde_yaml::Value::Bool(*b),
         UntaggedValue::Primitive(Primitive::Bytes(b)) => {
-            serde_yaml::Value::Number(serde_yaml::Number::from(b.to_f64().unwrap()))
-        }
-        UntaggedValue::Primitive(Primitive::Duration(secs)) => {
-            serde_yaml::Value::Number(serde_yaml::Number::from(secs.to_f64().unwrap()))
+            serde_yaml::Value::Number(serde_yaml::Number::from(b.to_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Could not convert to bytes",
+                    "could not convert to bytes",
+                    &v.tag,
+                )
+            })?))
         }
+        UntaggedValue::Primitive(Primitive::Duration(secs)) => serde_yaml::Value::Number(
+            serde_yaml::Number::from(secs.to_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Could not convert to duration",
+                    "could not convert to duration",
+                    &v.tag,
+                )
+            })?),
+        ),
         UntaggedValue::Primitive(Primitive::Date(d)) => serde_yaml::Value::String(d.to_string()),
         UntaggedValue::Primitive(Primitive::EndOfStream) => serde_yaml::Value::Null,
         UntaggedValue::Primitive(Primitive::BeginningOfStream) => serde_yaml::Value::Null,
         UntaggedValue::Primitive(Primitive::Decimal(f)) => {
-            serde_yaml::Value::Number(serde_yaml::Number::from(f.to_f64().unwrap()))
+            serde_yaml::Value::Number(serde_yaml::Number::from(f.to_f64().ok_or_else(|| {
+                ShellError::labeled_error(
+                    "Could not convert to decimal",
+                    "could not convert to decimal",
+                    &v.tag,
+                )
+            })?))
         }
         UntaggedValue::Primitive(Primitive::Int(i)) => {
             serde_yaml::Value::Number(serde_yaml::Number::from(CoerceInto::<i64>::coerce_into(
diff --git a/src/context.rs b/src/context.rs
index 19ca43039..806c31fd1 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -107,7 +107,7 @@ impl CommandRegistry {
 #[derive(Clone)]
 pub struct Context {
     pub registry: CommandRegistry,
-    pub host: Arc<Mutex<Box<dyn Host>>>,
+    pub host: Arc<parking_lot::Mutex<Box<dyn Host>>>,
     pub current_errors: Arc<Mutex<Vec<ShellError>>>,
     pub ctrl_c: Arc<AtomicBool>,
     pub(crate) shell_manager: ShellManager,
@@ -133,7 +133,9 @@ impl Context {
         let registry = CommandRegistry::new();
         Ok(Context {
             registry: registry.clone(),
-            host: Arc::new(Mutex::new(Box::new(crate::env::host::BasicHost))),
+            host: Arc::new(parking_lot::Mutex::new(Box::new(
+                crate::env::host::BasicHost,
+            ))),
             current_errors: Arc::new(Mutex::new(vec![])),
             ctrl_c: Arc::new(AtomicBool::new(false)),
             shell_manager: ShellManager::basic(registry)?,
@@ -161,14 +163,7 @@ impl Context {
                 );
                 result = false;
             }
-            (_, Err(err)) => {
-                errln!(
-                    "Unexpected error attempting to acquire the lock of the current errors: {:?}",
-                    err
-                );
-                result = false;
-            }
-            (Ok(mut errors), Ok(host)) => {
+            (Ok(mut errors), host) => {
                 if errors.len() > 0 {
                     let error = errors[0].clone();
                     *errors = vec![];
@@ -188,13 +183,8 @@ impl Context {
         &mut self,
         block: impl FnOnce(&mut dyn Host) -> T,
     ) -> Result<T, ShellError> {
-        if let Ok(mut host) = self.host.lock() {
-            Ok(block(&mut *host))
-        } else {
-            Err(ShellError::untagged_runtime_error(
-                "Internal error: could not lock host in with_host",
-            ))
-        }
+        let mut host = self.host.lock();
+        Ok(block(&mut *host))
     }
 
     pub(crate) fn with_errors<T>(
diff --git a/src/env/host.rs b/src/env/host.rs
index b8fd61d26..554ec324b 100644
--- a/src/env/host.rs
+++ b/src/env/host.rs
@@ -4,8 +4,8 @@ use nu_errors::ShellError;
 use std::fmt::Debug;
 
 pub trait Host: Debug + Send {
-    fn out_terminal(&self) -> Box<term::StdoutTerminal>;
-    fn err_terminal(&self) -> Box<term::StderrTerminal>;
+    fn out_terminal(&self) -> Option<Box<term::StdoutTerminal>>;
+    fn err_terminal(&self) -> Option<Box<term::StderrTerminal>>;
 
     fn out_termcolor(&self) -> termcolor::StandardStream;
     fn err_termcolor(&self) -> termcolor::StandardStream;
@@ -17,11 +17,11 @@ pub trait Host: Debug + Send {
 }
 
 impl Host for Box<dyn Host> {
-    fn out_terminal(&self) -> Box<term::StdoutTerminal> {
+    fn out_terminal(&self) -> Option<Box<term::StdoutTerminal>> {
         (**self).out_terminal()
     }
 
-    fn err_terminal(&self) -> Box<term::StderrTerminal> {
+    fn err_terminal(&self) -> Option<Box<term::StderrTerminal>> {
         (**self).err_terminal()
     }
 
@@ -50,12 +50,12 @@ impl Host for Box<dyn Host> {
 pub struct BasicHost;
 
 impl Host for BasicHost {
-    fn out_terminal(&self) -> Box<term::StdoutTerminal> {
-        term::stdout().unwrap()
+    fn out_terminal(&self) -> Option<Box<term::StdoutTerminal>> {
+        term::stdout()
     }
 
-    fn err_terminal(&self) -> Box<term::StderrTerminal> {
-        term::stderr().unwrap()
+    fn err_terminal(&self) -> Option<Box<term::StderrTerminal>> {
+        term::stderr()
     }
 
     fn stdout(&mut self, out: &str) {
diff --git a/src/format/table.rs b/src/format/table.rs
index 49984d6b9..9e317135c 100644
--- a/src/format/table.rs
+++ b/src/format/table.rs
@@ -326,13 +326,16 @@ impl RenderView for TableView {
 
         let mut table = Table::new();
 
-        let table_mode = crate::data::config::config(Tag::unknown())?
-            .get("table_mode")
-            .map(|s| match s.as_string().unwrap().as_ref() {
-                "light" => TableMode::Light,
+        let table_mode = crate::data::config::config(Tag::unknown());
+
+        let table_mode = if let Some(s) = table_mode?.get("table_mode") {
+            match s.as_string() {
+                Ok(typ) if typ == "light" => TableMode::Light,
                 _ => TableMode::Normal,
-            })
-            .unwrap_or(TableMode::Normal);
+            }
+        } else {
+            TableMode::Normal
+        };
 
         match table_mode {
             TableMode::Light => {
@@ -376,7 +379,8 @@ impl RenderView for TableView {
             ));
         }
 
-        table.print_term(&mut *host.out_terminal()).map_err(|_| ShellError::untagged_runtime_error("Internal error: could not print to terminal (for unix systems check to make sure TERM is set)"))?;
+        table.print_term(&mut *host.out_terminal().ok_or_else(|| ShellError::untagged_runtime_error("Could not open terminal for output"))?)
+            .map_err(|_| ShellError::untagged_runtime_error("Internal error: could not print to terminal (for unix systems check to make sure TERM is set)"))?;
 
         Ok(())
     }
diff --git a/src/prelude.rs b/src/prelude.rs
index cc5d1c196..2037bbf6d 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -99,7 +99,7 @@ pub(crate) use num_traits::cast::ToPrimitive;
 pub(crate) use serde::Deserialize;
 pub(crate) use std::collections::VecDeque;
 pub(crate) use std::future::Future;
-pub(crate) use std::sync::{Arc, Mutex};
+pub(crate) use std::sync::Arc;
 
 pub(crate) use itertools::Itertools;
 
diff --git a/src/shell/filesystem_shell.rs b/src/shell/filesystem_shell.rs
index ead246d37..5750d7b12 100644
--- a/src/shell/filesystem_shell.rs
+++ b/src/shell/filesystem_shell.rs
@@ -59,12 +59,9 @@ impl FilesystemShell {
         })
     }
 
-    pub fn with_location(
-        path: String,
-        commands: CommandRegistry,
-    ) -> Result<FilesystemShell, std::io::Error> {
+    pub fn with_location(path: String, commands: CommandRegistry) -> FilesystemShell {
         let last_path = path.clone();
-        Ok(FilesystemShell {
+        FilesystemShell {
             path,
             last_path,
             completer: NuCompleter {
@@ -72,7 +69,7 @@ impl FilesystemShell {
                 commands,
             },
             hinter: HistoryHinter {},
-        })
+        }
     }
 }