Update to Rust 1.94

.github/workflows/main.yml

@@ -15,8 +15,8 @@ jobs:
     - name: Install Rust
       run: |
         rustup set profile minimal
-        rustup toolchain install 1.93 -c rust-docs
-        rustup default 1.93
+        rustup toolchain install 1.94 -c rust-docs
+        rustup default 1.94
     - name: Install mdbook
       run: |
         mkdir bin
@@ -50,8 +50,8 @@ jobs:
     - name: Install Rust
       run: |
         rustup set profile minimal
-        rustup toolchain install 1.93 -c rust-docs
-        rustup default 1.93
+        rustup toolchain install 1.94 -c rust-docs
+        rustup default 1.94
     - name: Run `tools` package tests
       run: |
         cargo test

listings/ch02-guessing-game-tutorial/listing-02-04/output.txt

@@ -18,9 +18,9 @@ error[E0308]: mismatched types
     = note: expected reference `&String`
                found reference `&{integer}`
 note: method defined here
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/core/src/cmp.rs:987:8
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/core/src/cmp.rs:991:8
     |
-987 |     fn cmp(&self, other: &Self) -> Ordering;
+991 |     fn cmp(&self, other: &Self) -> Ordering;
     |        ^^^
 
 For more information about this error, try `rustc --explain E0308`.

listings/ch06-enums-and-pattern-matching/no-listing-07-cant-use-option-directly/output.txt

@@ -8,15 +8,24 @@ error[E0277]: cannot add `Option<i8>` to `i8`
     |
     = help: the trait `Add<Option<i8>>` is not implemented for `i8`
 help: the following other types implement trait `Add<Rhs>`
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/core/src/ops/arith.rs:114:1
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/core/src/ops/arith.rs:99:9
     |
+ 99 |         impl const Add for $t {
+    |         ^^^^^^^^^^^^^^^^^^^^^ `i8` implements `Add`
+...
 114 | add_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f16 f32 f64 f128 }
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    | |
-    | `&i8` implements `Add<i8>`
-    | `&i8` implements `Add`
-    | `i8` implements `Add<&i8>`
-    | `i8` implements `Add`
+    | ---------------------------------------------------------------------------------- in this macro invocation
+    |
+   ::: /Users/carolnichols/.rustup/toolchains/1.94-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/internal_macros.rs:22:9
+    |
+ 22 |         impl const $imp<$u> for &$t {
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&i8` implements `Add<i8>`
+...
+ 33 |         impl const $imp<&$u> for $t {
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `i8` implements `Add<&i8>`
+...
+ 44 |         impl const $imp<&$u> for &$t {
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&i8` implements `Add`
     = note: this error originates in the macro `add_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 For more information about this error, try `rustc --explain E0277`.

listings/ch06-enums-and-pattern-matching/no-listing-10-non-exhaustive-match/output.txt

@@ -7,7 +7,7 @@ error[E0004]: non-exhaustive patterns: `None` not covered
     |               ^ pattern `None` not covered
     |
 note: `Option<i32>` defined here
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/core/src/option.rs:600:1
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/core/src/option.rs:600:1
     |
 600 | pub enum Option<T> {
     | ^^^^^^^^^^^^^^^^^^

listings/ch08-common-collections/listing-08-19/output.txt

@@ -10,12 +10,12 @@ error[E0277]: the type `str` cannot be indexed by `{integer}`
     = note: you can use `.chars().nth()` or `.bytes().nth()`
             for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
 help: the following other types implement trait `SliceIndex<T>`
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/core/src/slice/index.rs:214:1
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/core/src/slice/index.rs:214:1
     |
 214 | unsafe impl<T> const SliceIndex<[T]> for usize {
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `usize` implements `SliceIndex<[T]>`
     |
-   ::: /Users/carolnichols/.rustup/toolchains/1.93-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/bstr/traits.rs:203:1
+   ::: /Users/carolnichols/.rustup/toolchains/1.94-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/bstr/traits.rs:203:1
     |
 203 | unsafe impl SliceIndex<ByteStr> for usize {
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `usize` implements `SliceIndex<ByteStr>`

listings/ch13-functional-features/listing-13-08/output.txt

@@ -14,7 +14,7 @@ error[E0507]: cannot move out of `value`, a captured variable in an `FnMut` clos
     |                              ^^^^^ `value` is moved here
     |
 help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but `FnOnce` closures may consume them only once
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/alloc/src/slice.rs:249:12
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/alloc/src/slice.rs:249:12
     |
 249 |         F: FnMut(&T) -> K,
     |            ^^^^^^^^^^^^^^

listings/ch15-smart-pointers/output-only-01-comparing-to-reference/output.txt

@@ -1,18 +1,18 @@
 $ cargo run
    Compiling deref-example v0.1.0 (file:///projects/deref-example)
 error[E0277]: can't compare `{integer}` with `&{integer}`
- --> src/main.rs:6:5
-  |
-6 |     assert_eq!(5, y);
-  |     ^^^^^^^^^^^^^^^^ no implementation for `{integer} == &{integer}`
-  |
-  = help: the trait `PartialEq<&{integer}>` is not implemented for `{integer}`
-  = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+  --> src/main.rs:6:5
+   |
+ 6 |     assert_eq!(5, y);
+   |     ^^^^^^^^^^^^^^^^ no implementation for `{integer} == &{integer}`
+   |
+   = help: the trait `PartialEq<&{integer}>` is not implemented for `{integer}`
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider dereferencing here
- --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/core/src/macros/mod.rs:46:35
-  |
-46|                 if !(*left_val == **right_val) {
-  |                                   +
+  --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/core/src/macros/mod.rs:46:35
+   |
+46 |                 if !(*left_val == **right_val) {
+   |                                   +
 
 For more information about this error, try `rustc --explain E0277`.
 error: could not compile `deref-example` (bin "deref-example") due to 1 previous error

listings/ch16-fearless-concurrency/listing-16-13/output.txt

@@ -13,14 +13,6 @@ error[E0382]: borrow of moved value: `counter`
 ...
 21 |     println!("Result: {}", *counter.lock().unwrap());
    |                             ^^^^^^^ value borrowed here after move
-   |
-help: consider moving the expression out of the loop so it is only moved once
-   |
- 8 ~     let mut value = counter.lock();
- 9 ~     for _ in 0..10 {
-10 |         let handle = thread::spawn(move || {
-11 ~             let mut num = value.unwrap();
-   |
 
 For more information about this error, try `rustc --explain E0382`.
 error: could not compile `shared-state` (bin "shared-state") due to 1 previous error

listings/ch16-fearless-concurrency/listing-16-14/output.txt

@@ -22,7 +22,7 @@ note: required because it's used within this closure
  11 |         let handle = thread::spawn(move || {
     |                                    ^^^^^^^
 note: required by a bound in `spawn`
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/std/src/thread/functions.rs:128:8
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/std/src/thread/functions.rs:128:8
     |
 125 | pub fn spawn<F, T>(f: F) -> JoinHandle<T>
     |        ----- required by a bound in this function

listings/ch18-oop/listing-18-10/output.txt

@@ -7,7 +7,7 @@ error[E0277]: the trait bound `String: Draw` is not satisfied
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Draw` is not implemented for `String`
    |
 help: the trait `Draw` is implemented for `Button`
-  --> /Users/carolnichols/rust/book/tmp/listings/ch18-oop/listing-18-10/src/lib.rs:23:1
+  --> src/lib.rs:23:1
    |
 23 | impl Draw for Button {
    | ^^^^^^^^^^^^^^^^^^^^

listings/ch21-web-server/listing-21-17/output.txt

@@ -16,12 +16,6 @@ note: consider changing this parameter type in method `new` to borrow instead if
    |
 47 |     fn new(id: usize, receiver: mpsc::Receiver<Job>) -> Worker {
    |        --- in this method       ^^^^^^^^^^^^^^^^^^^ this parameter takes ownership of the value
-help: consider moving the expression out of the loop so it is only moved once
-   |
-25 ~         let mut value = Worker::new(id, receiver);
-26 ~         for id in 0..size {
-27 ~             workers.push(value);
-   |
 
 For more information about this error, try `rustc --explain E0382`.
 error: could not compile `hello` (lib) due to 1 previous error

listings/ch21-web-server/listing-21-22/output.txt

@@ -9,9 +9,9 @@ error[E0507]: cannot move out of `worker.thread` which is behind a mutable refer
     |             move occurs because `worker.thread` has type `JoinHandle<()>`, which does not implement the `Copy` trait
     |
 note: `JoinHandle::<T>::join` takes ownership of the receiver `self`, which moves `worker.thread`
-   --> file:///home/.rustup/toolchains/1.93/lib/rustlib/src/rust/library/std/src/thread/join_handle.rs:148:17
+   --> file:///home/.rustup/toolchains/1.94/lib/rustlib/src/rust/library/std/src/thread/join_handle.rs:147:17
     |
-148 |     pub fn join(self) -> Result<T> {
+147 |     pub fn join(self) -> Result<T> {
     |                 ^^^^
 
 For more information about this error, try `rustc --explain E0507`.

rust-toolchain

@@ -1 +1 @@
-1.93
+1.94

src/title-page.md

@@ -3,7 +3,7 @@
 _by Steve Klabnik, Carol Nichols, and Chris Krycho, with contributions from the
 Rust Community_
 
-This version of the text assumes you’re using Rust 1.93.1 (released 2026-02-12)
+This version of the text assumes you’re using Rust 1.94.1 (released 2026-03-26)
 or later with `edition = "2024"` in the *Cargo.toml* file of all projects to
 configure them to use Rust 2024 Edition idioms. See the [“Installation” section
 of Chapter 1][install]<!-- ignore --> for instructions on installing or