diff --git a/crates/ruff_annotate_snippets/Cargo.toml b/crates/ruff_annotate_snippets/Cargo.toml
index 99bad240ae4e9f..0407984d3f59fb 100644
--- a/crates/ruff_annotate_snippets/Cargo.toml
+++ b/crates/ruff_annotate_snippets/Cargo.toml
@@ -56,7 +56,6 @@ filter_map_next = "warn"
 flat_map_option = "warn"
 float_cmp_const = "warn"
 fn_params_excessive_bools = "warn"
-from_iter_instead_of_collect = "warn"
 if_same_then_else = "allow"
 implicit_clone = "warn"
 imprecise_flops = "warn"
diff --git a/crates/ruff_linter/src/linter.rs b/crates/ruff_linter/src/linter.rs
index fc07c4e93c66f9..c04e3001af6b17 100644
--- a/crates/ruff_linter/src/linter.rs
+++ b/crates/ruff_linter/src/linter.rs
@@ -1059,7 +1059,7 @@ mod tests {
             },
         );
         insta::with_settings!({filters => vec![(r"\\", "/")]}, {
-                assert_diagnostics!(format!("{snapshot}"), diagnostics);
+                assert_diagnostics!(snapshot, diagnostics);
         });
 
         Ok(())
diff --git a/crates/ruff_linter/src/noqa.rs b/crates/ruff_linter/src/noqa.rs
index 9c8b973e4c6682..3388be09799f5b 100644
--- a/crates/ruff_linter/src/noqa.rs
+++ b/crates/ruff_linter/src/noqa.rs
@@ -3350,7 +3350,7 @@ mod tests {
             PreviewMode::Disabled,
         );
         assert_eq!(count, 0);
-        assert_eq!(output, format!("{contents}"));
+        assert_eq!(output, contents.to_string());
 
         let source_file = SourceFileBuilder::new(path.to_string_lossy(), contents).finish();
         let messages = [UnusedVariable {
diff --git a/crates/ruff_r2il/Cargo.toml b/crates/ruff_r2il/Cargo.toml
index d89bc483134489..c7ff5b088292fc 100644
--- a/crates/ruff_r2il/Cargo.toml
+++ b/crates/ruff_r2il/Cargo.toml
@@ -4,8 +4,8 @@ version = "0.1.0"
 publish = false
 # Excluded from the ruff workspace (root `exclude`), so nothing here can inherit from
 # [workspace.package] / [workspace.dependencies] / [workspace.lints]. edition/rust-version are
-# pinned by hand to satisfy BOTH sides: ruff (edition 2024, rust-version 1.93, toolchain 1.97.1)
-# and r2sleigh (edition 2024).
+# pinned by hand to satisfy BOTH sides: ruff (edition 2024, rust-version per the workspace
+# Cargo.toml, toolchain per rust-toolchain.toml) and r2sleigh (edition 2024).
 edition = "2024"
 rust-version = "1.93"
 description = "R2IL intake arm: a lossless ore carrier over r2sleigh's r2il/r2ssa object graph, a furnace that melts it into flat facet-addressed concern rows, and an addressed residual (slag) ledger. Ore in, named slag out — no catch-all, nothing dropped."
diff --git a/crates/ty_python_semantic/src/types/infer/tests.rs b/crates/ty_python_semantic/src/types/infer/tests.rs
index 223deb1cb4277d..04fe3034a8ea2b 100644
--- a/crates/ty_python_semantic/src/types/infer/tests.rs
+++ b/crates/ty_python_semantic/src/types/infer/tests.rs
@@ -1,3 +1,5 @@
+use std::fmt::Write as _;
+
 use super::builder::TypeInferenceBuilder;
 use crate::db::tests::{TestDb, TestDbBuilder, setup_db};
 use crate::place::symbol;
@@ -582,7 +584,8 @@ class Ui:
             );
 
             for index in 0..MANY_WIDGETS {
-                ui.push_str(&format!(
+                let _ = write!(
+                    ui,
                     concat!(
                         "        self.widget_{index} = Widget()\n",
                         "        self.widget_{index}.configure()\n",
@@ -590,7 +593,7 @@ class Ui:
                         "        self.widget_{index}.configure()\n",
                     ),
                     index = index,
-                ));
+                );
             }
             ui.push_str("        self.target = Widget()\n");
 
@@ -639,7 +642,8 @@ class Inner:
 "#,
             );
             for index in 0..MANY_WIDGETS {
-                inner.push_str(&format!(
+                let _ = write!(
+                    inner,
                     concat!(
                         "        self.widget_{index} = Widget()\n",
                         "        self.widget_{index}.configure()\n",
@@ -647,7 +651,7 @@ class Inner:
                         "        self.widget_{index}.configure()\n",
                     ),
                     index = index,
-                ));
+                );
             }
             inner.push_str("        self.target = Widget()\n");
 
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 72436043232cab..642220914d8a76 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,2 +1,2 @@
 [toolchain]
-channel = "1.97.1"
+channel = "1.98.1"