diff --git a/src/builder.rs b/src/builder.rs
index 7a89085..481096d 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -719,7 +719,7 @@ impl<D: Clone> ImplementationBuilder<MariaDbDatabase<D>> for DefaultBuilder {
 
 impl<D: Clone> ImplementationBuilder<PostgresqlDatabase<D>> for DefaultBuilder {
   type Prerequisites = ();
-  fn prerequisites(resource: &PostgresqlDatabase<D>) -> Self::Prerequisites {
+  fn prerequisites(_: &PostgresqlDatabase<D>) -> Self::Prerequisites {
     ()
   }
 
diff --git a/src/command_runner.rs b/src/command_runner.rs
index 5d8fd2f..b69e7ee 100644
--- a/src/command_runner.rs
+++ b/src/command_runner.rs
@@ -125,8 +125,8 @@ impl<U: AsRef<str>, C: CommandRunner> CommandRunner for SetuidCommandRunner<'_,
     let uid = get_user_by_name(self.user_name.as_ref())
       .expect("User does not exist")
       .uid();
-    let _set_home = TempSetEnv::new("HOME", format!("/home/{}", self.user_name.as_ref()));
-    let _set_dbus = TempSetEnv::new("XDG_RUNTIME_DIR", format!("/run/user/{}", uid));
+    let set_home = TempSetEnv::new("HOME", format!("/home/{}", self.user_name.as_ref()));
+    let set_dbus = TempSetEnv::new("XDG_RUNTIME_DIR", format!("/run/user/{}", uid));
     //println!("{} {:?}", program, args);
     let mut child = Command::new(program)
       .args(args)
@@ -143,6 +143,8 @@ impl<U: AsRef<str>, C: CommandRunner> CommandRunner for SetuidCommandRunner<'_,
       .await
       .expect("Failed to write to stdin");
     let res = child.wait_with_output().await;
+    drop(set_home);
+    drop(set_dbus);
     //println!("{:?}", res);
     res
   }
diff --git a/src/locator.rs b/src/locator.rs
index bdf17a7..739c8c3 100644
--- a/src/locator.rs
+++ b/src/locator.rs
@@ -15,23 +15,29 @@ use std::marker::PhantomData;
 use std::path::{Path, PathBuf};
 
 pub trait Policy {
+  #[must_use]
   fn acme_user() -> &'static str {
     "acme"
   }
+
+  #[must_use]
   fn user_home(user_name: &str) -> PathBuf {
-    format!("/home/{}", user_name).into()
+    Path::new("/home").join(user_name)
   }
 
+  #[must_use]
   fn user_name_for_domain(domain_name: &'_ str) -> String {
     domain_name.split('.').rev().fold(String::new(), |result, part| if result.is_empty() { result } else { result + "_" } + part)
   }
 
+  #[must_use]
   fn php_version() -> &'static str {
     "7.0"
   }
 
+  #[must_use]
   fn path_for_data(name: impl Display) -> PathBuf {
-    ("/root/data".as_ref() as &Path).join(format!("_{}", name))
+    Path::new("/root/data").join(format!("_{}", name))
   }
 }
 
@@ -286,7 +292,7 @@ impl<D: AsRef<Path>, POLICY> ResourceLocator<ServeCustom<D>> for DefaultLocator<
     resource: &ServeCustom<D>,
   ) -> (<ServeCustom<D> as Resource>::Artifact, Self::Prerequisites) {
     (
-      PathArtifact::from(("/etc/nginx/sites-enabled/".as_ref() as &Path).join(&resource.0)),
+      PathArtifact::from(Path::new("/etc/nginx/sites-enabled/").join(&resource.0)),
       (),
     )
   }
@@ -298,7 +304,7 @@ impl<D: AsRef<Path>, P, POLICY> ResourceLocator<ServePhp<D, P>> for DefaultLocat
     resource: &ServePhp<D, P>,
   ) -> (<ServePhp<D, P> as Resource>::Artifact, Self::Prerequisites) {
     (
-      PathArtifact::from(("/etc/nginx/sites-enabled/".as_ref() as &Path).join(&resource.0)),
+      PathArtifact::from(Path::new("/etc/nginx/sites-enabled/").join(&resource.0)),
       (),
     )
   }
@@ -313,7 +319,7 @@ impl<D: AsRef<Path>, P, POLICY> ResourceLocator<ServeService<D, P>> for DefaultL
     Self::Prerequisites,
   ) {
     (
-      PathArtifact::from(("/etc/nginx/sites-enabled/".as_ref() as &Path).join(&resource.0)),
+      PathArtifact::from(Path::new("/etc/nginx/sites-enabled/").join(&resource.0)),
       (),
     )
   }
@@ -325,7 +331,7 @@ impl<D: AsRef<Path>, POLICY> ResourceLocator<ServeRedir<D>> for DefaultLocator<P
     resource: &ServeRedir<D>,
   ) -> (<ServeRedir<D> as Resource>::Artifact, Self::Prerequisites) {
     (
-      PathArtifact::from(("/etc/nginx/sites-enabled/".as_ref() as &Path).join(&resource.0)),
+      PathArtifact::from(Path::new("/etc/nginx/sites-enabled/").join(&resource.0)),
       (),
     )
   }
@@ -340,7 +346,7 @@ impl<D: AsRef<Path>, P, POLICY> ResourceLocator<ServeStatic<D, P>> for DefaultLo
     Self::Prerequisites,
   ) {
     (
-      PathArtifact::from(("/etc/nginx/sites-enabled/".as_ref() as &Path).join(&resource.0)),
+      PathArtifact::from(Path::new("/etc/nginx/sites-enabled/").join(&resource.0)),
       (),
     )
   }
diff --git a/src/setup/runnable.rs b/src/setup/runnable.rs
index 5c3a1c3..add3f49 100644
--- a/src/setup/runnable.rs
+++ b/src/setup/runnable.rs
@@ -32,6 +32,7 @@ where
 
 macro_rules! runnable_for_tuple {
   ( $($name:ident)* ) => (
+    #[allow(clippy::let_unit_value)]
     #[async_trait(?Send)]
     #[allow(non_snake_case)]
     impl<$($name: Symbol + Debug,)*> Runnable for ($($name,)*) {
@@ -117,7 +118,7 @@ mod test {
     async fn run_symbol<S: Symbol + Debug, L: Logger>(
       &self,
       symbol: &S,
-      logger: &L,
+      _logger: &L,
       force: bool,
     ) -> Result<bool, Box<dyn Error>> {
       let run = force || !symbol.target_reached().await?;
diff --git a/src/setup/setup.rs b/src/setup/setup.rs
index 4efd0ab..842152b 100644
--- a/src/setup/setup.rs
+++ b/src/setup/setup.rs
@@ -201,7 +201,7 @@ mod test {
     async fn run_symbol<S: Symbol + Debug, L: Logger>(
       &self,
       symbol: &S,
-      logger: &L,
+      _logger: &L,
       force: bool,
     ) -> Result<bool, Box<dyn Error>> {
       let run = force || !symbol.target_reached().await?;
@@ -239,7 +239,7 @@ mod test {
   #[derive(Clone)]
   struct Artifacts;
   impl<V> FromArtifact<TestResource<V>> for Artifacts {
-    fn from_artifact(from: ()) -> Self {
+    fn from_artifact(_from: ()) -> Self {
       Self
     }
     fn into_artifact(self) -> () {
diff --git a/src/setup/symbol_runner.rs b/src/setup/symbol_runner.rs
index 5448521..378cd90 100644
--- a/src/setup/symbol_runner.rs
+++ b/src/setup/symbol_runner.rs
@@ -17,27 +17,14 @@ pub trait SymbolRunner {
   ) -> Result<bool, Box<dyn Error>>;
 }
 
-#[derive(Debug)]
-pub enum SymbolRunError {
-  Symbol(Box<dyn Error>),
-  ExecuteDidNotReach(()),
-}
+#[derive(Debug, Default)]
+pub struct ExecuteDidNotReachError;
 
-impl Error for SymbolRunError {
-  fn cause(&self) -> Option<&dyn Error> {
-    match self {
-      Self::Symbol(ref e) => Some(&**e),
-      Self::ExecuteDidNotReach(_) => None,
-    }
-  }
-}
+impl Error for ExecuteDidNotReachError {}
 
-impl fmt::Display for SymbolRunError {
+impl fmt::Display for ExecuteDidNotReachError {
   fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-    match self {
-      Self::Symbol(ref e) => write!(f, "{}", e),
-      Self::ExecuteDidNotReach(_) => write!(f, "Target not reached after executing symbol"),
-    }
+    write!(f, "Target not reached after executing symbol")
   }
 }
 
@@ -45,7 +32,8 @@ impl fmt::Display for SymbolRunError {
 pub struct InitializingSymbolRunner;
 
 impl InitializingSymbolRunner {
-  pub fn new() -> Self {
+  #[must_use]
+  pub const fn new() -> Self {
     Self
   }
 
@@ -64,7 +52,7 @@ impl InitializingSymbolRunner {
     if target_reached {
       Ok(())
     } else {
-      Err(Box::new(SymbolRunError::ExecuteDidNotReach(())))
+      Err(Box::new(ExecuteDidNotReachError))
     }
   }
 }
@@ -102,7 +90,8 @@ impl SymbolRunner for InitializingSymbolRunner {
 pub struct DelayingSymbolRunner<R>(R);
 
 impl<R> DelayingSymbolRunner<R> {
-  pub fn new(symbol_runner: R) -> Self {
+  #[must_use]
+  pub const fn new(symbol_runner: R) -> Self {
     Self(symbol_runner)
   }
 }
@@ -137,7 +126,8 @@ where
 pub struct DrySymbolRunner;
 
 impl DrySymbolRunner {
-  pub fn new() -> Self {
+  #[must_use]
+  pub const fn new() -> Self {
     Self
   }
 }
@@ -172,7 +162,8 @@ impl SymbolRunner for DrySymbolRunner {
 pub struct ReportingSymbolRunner<R>(R);
 
 impl<R> ReportingSymbolRunner<R> {
-  pub fn new(symbol_runner: R) -> Self {
+  #[must_use]
+  pub const fn new(symbol_runner: R) -> Self {
     Self(symbol_runner)
   }
 }
@@ -251,6 +242,7 @@ mod test {
       T: Iterator<Item = Result<bool, Box<dyn Error>>>,
     > DummySymbol<T, E>
   {
+    #[must_use]
     fn new<
       IE: IntoIterator<IntoIter = E, Item = Result<(), Box<dyn Error>>>,
       IT: IntoIterator<IntoIter = T, Item = Result<bool, Box<dyn Error>>>,
diff --git a/src/symbols/git/checkout.rs b/src/symbols/git/checkout.rs
index e2ad4a5..14593ba 100644
--- a/src/symbols/git/checkout.rs
+++ b/src/symbols/git/checkout.rs
@@ -63,7 +63,12 @@ impl<C: CommandRunner, _C: Borrow<C>, P: AsRef<Path>, S: AsRef<str>, B: AsRef<st
   }
 
   async fn execute(&self) -> Result<(), Box<dyn Error>> {
-    if !self.target.as_ref().exists() {
+    if self.target.as_ref().exists() {
+      self
+        .run_git(&["fetch", self.source.as_ref(), self.branch.as_ref()])
+        .await?;
+      self.run_git(&["merge", "FETCH_HEAD"]).await?;
+    } else {
       self
         .command_runner
         .borrow()
@@ -80,11 +85,6 @@ impl<C: CommandRunner, _C: Borrow<C>, P: AsRef<Path>, S: AsRef<str>, B: AsRef<st
           ],
         )
         .await?;
-    } else {
-      self
-        .run_git(&["fetch", self.source.as_ref(), self.branch.as_ref()])
-        .await?;
-      self.run_git(&["merge", "FETCH_HEAD"]).await?;
     }
     Ok(())
   }
diff --git a/src/symbols/user.rs b/src/symbols/user.rs
index 5d54f3f..3c67809 100644
--- a/src/symbols/user.rs
+++ b/src/symbols/user.rs
@@ -41,7 +41,7 @@ impl<U: AsRef<str>, C: CommandRunner> Symbol for User<U, C> {
     // adduser is not reentrant because finding the next uid
     // and creating the account is not an atomic operation
     let wait = WAIT.acquire().await;
-    self
+    let res = self
       .command_runner
       .run_successfully(
         "adduser",
@@ -51,7 +51,9 @@ impl<U: AsRef<str>, C: CommandRunner> Symbol for User<U, C> {
           self.user_name.as_ref(),
         ],
       )
-      .await
+      .await;
+    drop(wait);
+    res
   }
 }
 
diff --git a/src/to_artifact.rs b/src/to_artifact.rs
index e158f07..e45cda9 100644
--- a/src/to_artifact.rs
+++ b/src/to_artifact.rs
@@ -17,6 +17,8 @@ macro_rules! to_artifact {
 for_each_tuple!(to_artifact);
 
 impl<T: Resource> ToArtifact for Option<T> {
+  // FIXME: https://github.com/rust-lang/rust-clippy/issues/2843
+  #![allow(clippy::use_self)]
   type Artifact = Option<T::Artifact>;
 }