diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5e0b9937..eeb91c2d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -90,8 +90,8 @@ jobs:
         #   https://github.com/rust-lang/rustup/issues/2441
         #
         # for more information.
-        rustup toolchain install 1.91.0 --no-self-update # [ref:rust_1.91.0]
-        rustup default 1.91.0 # [ref:rust_1.91.0]
+        rustup toolchain install 1.92.0 --no-self-update # [ref:rust_1.92.0]
+        rustup default 1.92.0 # [ref:rust_1.92.0]
 
         # Add the targets.
         rustup target add x86_64-pc-windows-msvc
@@ -131,8 +131,8 @@ jobs:
         set -euxo pipefail
 
         # Install the appropriate version of Rust.
-        rustup toolchain install 1.91.0 # [ref:rust_1.91.0]
-        rustup default 1.91.0 # [ref:rust_1.91.0]
+        rustup toolchain install 1.92.0 # [ref:rust_1.92.0]
+        rustup default 1.92.0 # [ref:rust_1.92.0]
 
         # Add the targets.
         rustup target add x86_64-apple-darwin
@@ -207,8 +207,8 @@ jobs:
         set -euxo pipefail
 
         # Install the appropriate version of Rust.
-        rustup toolchain install 1.91.0 # [ref:rust_1.91.0]
-        rustup default 1.91.0 # [ref:rust_1.91.0]
+        rustup toolchain install 1.92.0 # [ref:rust_1.92.0]
+        rustup default 1.92.0 # [ref:rust_1.92.0]
 
         # Fetch the program version.
         VERSION="$(cargo pkgid | cut -d# -f2 | cut -d: -f2)"
diff --git a/src/assertions.rs b/src/assertions.rs
index d08a502b..df42cb2f 100644
--- a/src/assertions.rs
+++ b/src/assertions.rs
@@ -58,10 +58,7 @@ macro_rules! assert_same {
 
 #[cfg(test)]
 mod tests {
-    use {
-        crate::{assert_fails, assert_same, error::Error},
-        std::fmt::Write,
-    };
+    use {crate::error::Error, std::fmt::Write};
 
     #[test]
     #[should_panic(expected = "The expression was supposed to fail, but it succeeded.")]
diff --git a/toast.yml b/toast.yml
index de606e4a..c5b8e7da 100644
--- a/toast.yml
+++ b/toast.yml
@@ -17,11 +17,11 @@ command_prefix: |
   cargo-offline () { cargo --frozen --offline "$@"; }
 
   # Use this wrapper for formatting code or checking that code is formatted. We use a nightly Rust
-  # version for the `trailing_comma` formatting option [tag:rust_fmt_nightly_2025-11-02]. The
+  # version for the `trailing_comma` formatting option [tag:rust_fmt_nightly_2025-12-11]. The
   # nightly version was chosen as the latest available release with all components present
   # according to this page:
   #   https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu.html
-  cargo-fmt () { cargo +nightly-2025-11-02 --frozen --offline fmt --all -- "$@"; }
+  cargo-fmt () { cargo +nightly-2025-12-11 --frozen --offline fmt --all -- "$@"; }
 
   # Load the NVM startup file, if it exists.
   if [ -f "$HOME/.nvm/nvm.sh" ]; then
@@ -75,18 +75,18 @@ tasks:
       - install_packages
       - create_user
     command: |
-      # Install stable Rust [tag:rust_1.91.0].
+      # Install stable Rust [tag:rust_1.92.0].
       curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- \
         -y \
-        --default-toolchain 1.91.0 \
+        --default-toolchain 1.92.0 \
         --profile minimal \
         --component clippy
 
       # Add Rust tools to `$PATH`.
       . "$HOME/.cargo/env"
 
-      # Install nightly Rust [ref:rust_fmt_nightly_2025-11-02].
-      rustup toolchain install nightly-2025-11-02 --profile minimal --component rustfmt
+      # Install nightly Rust [ref:rust_fmt_nightly_2025-12-11].
+      rustup toolchain install nightly-2025-12-11 --profile minimal --component rustfmt
 
   install_node:
     description: Install Node.js, a JavaScript runtime environment.