diff --git a/src/bootstrap/src/core/build_steps/check.rs b/src/bootstrap/src/core/build_steps/check.rs
index 7fd811ac5071..46fad688ebaa 100644
--- a/src/bootstrap/src/core/build_steps/check.rs
+++ b/src/bootstrap/src/core/build_steps/check.rs
@@ -344,7 +344,7 @@ impl Step for RustAnalyzer {
                 .config
                 .tools
                 .as_ref()
-                .map_or(true, |tools| tools.iter().any(|tool| tool == "rust-analyzer")),
+                .is_none_or(|tools| tools.iter().any(|tool| tool == "rust-analyzer")),
         )
     }
 
diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index b4c56df6ea6d..2dc3873569e5 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -1673,10 +1673,10 @@ impl Step for Sysroot {
             ];
             let ci_rustc_dir = builder.config.ci_rustc_dir();
             builder.cp_link_filtered(&ci_rustc_dir, &sysroot, &|path| {
-                if path.extension().map_or(true, |ext| !filtered_extensions.contains(&ext)) {
+                if path.extension().is_none_or(|ext| !filtered_extensions.contains(&ext)) {
                     return true;
                 }
-                if !path.parent().map_or(true, |p| p.ends_with(&suffix)) {
+                if !path.parent().is_none_or(|p| p.ends_with(&suffix)) {
                     return true;
                 }
                 if !filtered_files.iter().all(|f| f != path.file_name().unwrap()) {
diff --git a/src/bootstrap/src/core/build_steps/dist.rs b/src/bootstrap/src/core/build_steps/dist.rs
index 8bfa9cc94b34..29bc0cbf58a8 100644
--- a/src/bootstrap/src/core/build_steps/dist.rs
+++ b/src/bootstrap/src/core/build_steps/dist.rs
@@ -47,7 +47,7 @@ fn should_build_extended_tool(builder: &Builder<'_>, tool: &str) -> bool {
     if !builder.config.extended {
         return false;
     }
-    builder.config.tools.as_ref().map_or(true, |tools| tools.contains(tool))
+    builder.config.tools.as_ref().is_none_or(|tools| tools.contains(tool))
 }
 
 #[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
@@ -410,7 +410,7 @@ impl Step for Rustc {
                 .config
                 .tools
                 .as_ref()
-                .map_or(true, |tools| tools.iter().any(|tool| tool == "rustdoc"))
+                .is_none_or(|tools| tools.iter().any(|tool| tool == "rustdoc"))
             {
                 let rustdoc = builder.rustdoc(compiler);
                 builder.install(&rustdoc, &image.join("bin"), 0o755);
diff --git a/src/bootstrap/src/core/build_steps/install.rs b/src/bootstrap/src/core/build_steps/install.rs
index b6862c2d5c4a..3ee95475e3ae 100644
--- a/src/bootstrap/src/core/build_steps/install.rs
+++ b/src/bootstrap/src/core/build_steps/install.rs
@@ -307,7 +307,7 @@ impl Step for Src {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let config = &run.builder.config;
-        let cond = config.extended && config.tools.as_ref().map_or(true, |t| t.contains("src"));
+        let cond = config.extended && config.tools.as_ref().is_none_or(|t|t.contains("src"));
         run.path("src").default_condition(cond)
     }
 
diff --git a/src/bootstrap/src/core/builder/mod.rs b/src/bootstrap/src/core/builder/mod.rs
index da2ce5b59763..3d01647aacc6 100644
--- a/src/bootstrap/src/core/builder/mod.rs
+++ b/src/bootstrap/src/core/builder/mod.rs
@@ -1443,7 +1443,7 @@ impl<'a> Builder<'a> {
             let mut stack = self.stack.borrow_mut();
             for stack_step in stack.iter() {
                 // should skip
-                if stack_step.downcast_ref::<S>().map_or(true, |stack_step| *stack_step != step) {
+                if stack_step.downcast_ref::<S>().is_none_or(|stack_step| *stack_step != step) {
                     continue;
                 }
                 let mut out = String::new();
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index dd2f11ad4690..acabfc3685e0 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1125,7 +1125,7 @@ impl<'de> Deserialize<'de> for LldMode {
                 match v {
                     "external" => Ok(LldMode::External),
                     "self-contained" => Ok(LldMode::SelfContained),
-                    _ => Err(E::custom("unknown mode {v}")),
+                    _ => Err(E::custom(format!("unknown mode {v}"))),
                 }
             }
         }