Update to Rust 1.55

2021-09-15 21:49:30 -04:00 · 2021-09-15 21:49:30 -04:00 · 126aa9faa8
parent e7d05cec4b
commit 126aa9faa8
72 changed files with 101 additions and 358 deletions
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@ -12,8 +12,8 @@ jobs:
    - name: Install Rust
      run: |
        rustup set profile minimal
-        rustup toolchain install 1.54 -c rust-docs
-        rustup default 1.54
+        rustup toolchain install 1.55 -c rust-docs
+        rustup default 1.55
    - name: Install mdbook
      run: |
        mkdir bin
--- a/listings/ch02-guessing-game-tutorial/listing-02-04/output.txt
+++ b/listings/ch02-guessing-game-tutorial/listing-02-04/output.txt
@ -16,9 +16,5 @@ error[E0308]: mismatched types
   = note: expected reference `&String`
              found reference `&{integer}`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `guessing_game`
-
-To learn more, run the command again with --verbose.
+error: could not compile `guessing_game` due to previous error
--- a/listings/ch02-guessing-game-tutorial/no-listing-02-without-expect/output.txt
+++ b/listings/ch02-guessing-game-tutorial/no-listing-02-without-expect/output.txt
@ -9,6 +9,5 @@ warning: unused `Result` that must be used
   = note: `#[warn(unused_must_use)]` on by default
   = note: this `Result` may be an `Err` variant, which should be handled

-warning: 1 warning emitted
-
+warning: `guessing_game` (bin "guessing_game") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.59s
--- a/listings/ch03-common-programming-concepts/no-listing-01-variables-are-immutable/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-01-variables-are-immutable/output.txt
@ -12,9 +12,5 @@ error[E0384]: cannot assign twice to immutable variable `x`
 4 |     x = 6;
  |     ^^^^^ cannot assign twice to immutable variable

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0384`.
-error: could not compile `variables`
-
-To learn more, run the command again with --verbose.
+error: could not compile `variables` due to previous error
--- a/listings/ch03-common-programming-concepts/no-listing-05-mut-cant-change-types/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-05-mut-cant-change-types/output.txt
@ -6,9 +6,5 @@ error[E0308]: mismatched types
 3 |     spaces = spaces.len();
  |              ^^^^^^^^^^^^ expected `&str`, found `usize`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `variables`
-
-To learn more, run the command again with --verbose.
+error: could not compile `variables` due to previous error
--- a/listings/ch03-common-programming-concepts/no-listing-19-statements-vs-expressions/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-19-statements-vs-expressions/output.txt
@ -25,9 +25,6 @@ warning: unnecessary parentheses around assigned value
  |
  = note: `#[warn(unused_parens)]` on by default

-error: aborting due to 2 previous errors; 1 warning emitted
-
 For more information about this error, try `rustc --explain E0658`.
-error: could not compile `functions`
-
-To learn more, run the command again with --verbose.
+warning: `functions` (bin "functions") generated 1 warning
+error: could not compile `functions` due to 2 previous errors; 1 warning emitted
--- a/listings/ch03-common-programming-concepts/no-listing-23-statements-dont-return-values/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-23-statements-dont-return-values/output.txt
@ -10,9 +10,5 @@ error[E0308]: mismatched types
 8 |     x + 1;
  |          - help: consider removing this semicolon

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `functions`
-
-To learn more, run the command again with --verbose.
+error: could not compile `functions` due to previous error
--- a/listings/ch03-common-programming-concepts/no-listing-28-if-condition-must-be-bool/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-28-if-condition-must-be-bool/output.txt
@ -6,9 +6,5 @@ error[E0308]: mismatched types
 4 |     if number {
  |        ^^^^^^ expected `bool`, found integer

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `branches`
-
-To learn more, run the command again with --verbose.
+error: could not compile `branches` due to previous error
--- a/listings/ch03-common-programming-concepts/no-listing-31-arms-must-return-same-type/output.txt
+++ b/listings/ch03-common-programming-concepts/no-listing-31-arms-must-return-same-type/output.txt
@ -8,9 +8,5 @@ error[E0308]: `if` and `else` have incompatible types
  |                                 |
  |                                 expected because of this

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `branches`
-
-To learn more, run the command again with --verbose.
+error: could not compile `branches` due to previous error
--- a/listings/ch03-common-programming-concepts/output-only-01-no-type-annotations/output.txt
+++ b/listings/ch03-common-programming-concepts/output-only-01-no-type-annotations/output.txt
@ -6,9 +6,5 @@ error[E0282]: type annotations needed
 2 |     let guess = "42".parse().expect("Not a number!");
  |         ^^^^^ consider giving `guess` a type

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0282`.
-error: could not compile `no_type_annotations`
-
-To learn more, run the command again with --verbose.
+error: could not compile `no_type_annotations` due to previous error
--- a/listings/ch04-understanding-ownership/listing-04-06/output.txt
+++ b/listings/ch04-understanding-ownership/listing-04-06/output.txt
@ -8,9 +8,5 @@ error[E0596]: cannot borrow `*some_string` as mutable, as it is behind a `&` ref
 8 |     some_string.push_str(", world");
  |     ^^^^^^^^^^^ `some_string` is a `&` reference, so the data it refers to cannot be borrowed as mutable

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0596`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch04-understanding-ownership/no-listing-04-cant-use-after-move/output.txt
+++ b/listings/ch04-understanding-ownership/no-listing-04-cant-use-after-move/output.txt
@ -11,9 +11,5 @@ error[E0382]: borrow of moved value: `s1`
 5 |     println!("{}, world!", s1);
  |                            ^^ value borrowed here after move

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch04-understanding-ownership/no-listing-10-multiple-mut-not-allowed/output.txt
+++ b/listings/ch04-understanding-ownership/no-listing-10-multiple-mut-not-allowed/output.txt
@ -11,9 +11,5 @@ error[E0499]: cannot borrow `s` as mutable more than once at a time
 7 |     println!("{}, {}", r1, r2);
  |                        -- first borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0499`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch04-understanding-ownership/no-listing-12-immutable-and-mutable-not-allowed/output.txt
+++ b/listings/ch04-understanding-ownership/no-listing-12-immutable-and-mutable-not-allowed/output.txt
@ -12,9 +12,5 @@ error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immuta
 8 |     println!("{}, {}, and {}", r1, r2, r3);
  |                                -- immutable borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0502`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch04-understanding-ownership/no-listing-14-dangling-reference/output.txt
+++ b/listings/ch04-understanding-ownership/no-listing-14-dangling-reference/output.txt
@ -12,9 +12,5 @@ help: consider using the `'static` lifetime
 5 | fn dangle() -> &'static String {
  |                ^^^^^^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0106`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch04-understanding-ownership/no-listing-19-slice-error/output.txt
+++ b/listings/ch04-understanding-ownership/no-listing-19-slice-error/output.txt
@ -12,9 +12,5 @@ error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immuta
 20 |     println!("the first word is: {}", word);
   |                                       ---- immutable borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0502`.
-error: could not compile `ownership`
-
-To learn more, run the command again with --verbose.
+error: could not compile `ownership` due to previous error
--- a/listings/ch05-using-structs-to-structure-related-data/listing-05-11/output.txt
+++ b/listings/ch05-using-structs-to-structure-related-data/listing-05-11/output.txt
@ -8,12 +8,7 @@ error[E0277]: `Rectangle` doesn't implement `std::fmt::Display`
   |
   = help: the trait `std::fmt::Display` is not implemented for `Rectangle`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
-   = note: required by `std::fmt::Display::fmt`
   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `rectangles`
-
-To learn more, run the command again with --verbose.
+error: could not compile `rectangles` due to previous error
--- a/listings/ch05-using-structs-to-structure-related-data/no-listing-02-reference-in-struct/output.txt
+++ b/listings/ch05-using-structs-to-structure-related-data/no-listing-02-reference-in-struct/output.txt
@ -1,33 +1,31 @@
 $ cargo run
   Compiling structs v0.1.0 (file:///projects/structs)
 error[E0106]: missing lifetime specifier
- --> src/main.rs:2:15
+ --> src/main.rs:3:15
  |
-2 |     username: &str,
+3 |     username: &str,
  |               ^ expected named lifetime parameter
  |
 help: consider introducing a named lifetime parameter
  |
 1 | struct User<'a> {
-2 |     username: &'a str,
+2 |     active: bool,
+3 |     username: &'a str,
  |

 error[E0106]: missing lifetime specifier
- --> src/main.rs:3:12
+ --> src/main.rs:4:12
  |
-3 |     email: &str,
+4 |     email: &str,
  |            ^ expected named lifetime parameter
  |
 help: consider introducing a named lifetime parameter
  |
 1 | struct User<'a> {
-2 |     username: &str,
-3 |     email: &'a str,
+2 |     active: bool,
+3 |     username: &str,
+4 |     email: &'a str,
  |

-error: aborting due to 2 previous errors
-
 For more information about this error, try `rustc --explain E0106`.
-error: could not compile `structs`
-
-To learn more, run the command again with --verbose.
+error: could not compile `structs` due to 2 previous errors
--- a/listings/ch05-using-structs-to-structure-related-data/output-only-01-debug/output.txt
+++ b/listings/ch05-using-structs-to-structure-related-data/output-only-01-debug/output.txt
@ -7,13 +7,8 @@ error[E0277]: `Rectangle` doesn't implement `Debug`
   |                               ^^^^^ `Rectangle` cannot be formatted using `{:?}`
   |
   = help: the trait `Debug` is not implemented for `Rectangle`
-   = note: add `#[derive(Debug)]` or manually implement `Debug`
-   = note: required by `std::fmt::Debug::fmt`
+   = note: add `#[derive(Debug)]` to `Rectangle` or manually `impl Debug for Rectangle`
   = note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info)

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `rectangles`
-
-To learn more, run the command again with --verbose.
+error: could not compile `rectangles` due to previous error
--- a/listings/ch06-enums-and-pattern-matching/no-listing-07-cant-use-option-directly/output.txt
+++ b/listings/ch06-enums-and-pattern-matching/no-listing-07-cant-use-option-directly/output.txt
@ -8,9 +8,5 @@ error[E0277]: cannot add `Option<i8>` to `i8`
  |
  = help: the trait `Add<Option<i8>>` is not implemented for `i8`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `enums`
-
-To learn more, run the command again with --verbose.
+error: could not compile `enums` due to previous error
--- a/listings/ch06-enums-and-pattern-matching/no-listing-10-non-exhaustive-match/output.txt
+++ b/listings/ch06-enums-and-pattern-matching/no-listing-10-non-exhaustive-match/output.txt
@ -9,9 +9,5 @@ error[E0004]: non-exhaustive patterns: `None` not covered
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
    = note: the matched value is of type `Option<i32>`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0004`.
-error: could not compile `enums`
-
-To learn more, run the command again with --verbose.
+error: could not compile `enums` due to previous error
--- a/listings/ch07-managing-growing-projects/listing-07-03/output.txt
+++ b/listings/ch07-managing-growing-projects/listing-07-03/output.txt
@ -24,9 +24,5 @@ note: the module `hosting` is defined here
 2  |     mod hosting {
   |     ^^^^^^^^^^^

-error: aborting due to 2 previous errors
-
 For more information about this error, try `rustc --explain E0603`.
-error: could not compile `restaurant`
-
-To learn more, run the command again with --verbose.
+error: could not compile `restaurant` due to 2 previous errors
--- a/listings/ch07-managing-growing-projects/listing-07-05/output.txt
+++ b/listings/ch07-managing-growing-projects/listing-07-05/output.txt
@ -24,9 +24,5 @@ note: the function `add_to_waitlist` is defined here
 3  |         fn add_to_waitlist() {}
   |         ^^^^^^^^^^^^^^^^^^^^

-error: aborting due to 2 previous errors
-
 For more information about this error, try `rustc --explain E0603`.
-error: could not compile `restaurant`
-
-To learn more, run the command again with --verbose.
+error: could not compile `restaurant` due to 2 previous errors
--- a/listings/ch08-common-collections/listing-08-07/output.txt
+++ b/listings/ch08-common-collections/listing-08-07/output.txt
@ -12,9 +12,5 @@ error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immuta
 8 |     println!("The first element is: {}", first);
  |                                          ----- immutable borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0502`.
-error: could not compile `collections`
-
-To learn more, run the command again with --verbose.
+error: could not compile `collections` due to previous error
--- a/listings/ch08-common-collections/listing-08-19/output.txt
+++ b/listings/ch08-common-collections/listing-08-19/output.txt
@ -8,9 +8,5 @@ error[E0277]: the type `String` cannot be indexed by `{integer}`
  |
  = help: the trait `Index<{integer}>` is not implemented for `String`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `collections`
-
-To learn more, run the command again with --verbose.
+error: could not compile `collections` due to previous error
--- a/listings/ch09-error-handling/no-listing-02-ask-compiler-for-type/output.txt
+++ b/listings/ch09-error-handling/no-listing-02-ask-compiler-for-type/output.txt
@ -11,9 +11,5 @@ error[E0308]: mismatched types
  = note: expected type `u32`
             found enum `Result<File, std::io::Error>`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `error-handling`
-
-To learn more, run the command again with --verbose.
+error: could not compile `error-handling` due to previous error
--- a/listings/ch09-error-handling/no-listing-06-question-mark-in-main/output.txt
+++ b/listings/ch09-error-handling/no-listing-06-question-mark-in-main/output.txt
@ -1,20 +1,16 @@
 $ cargo run
   Compiling error-handling v0.1.0 (file:///projects/error-handling)
 error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
- --> src/main.rs:4:36
-  |
-3 | / fn main() {
-4 | |     let f = File::open("hello.txt")?;
-  | |                                    ^ cannot use the `?` operator in a function that returns `()`
-5 | | }
-  | |_- this function should return `Result` or `Option` to accept `?`
-  |
-  = help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
-  = note: required by `from_residual`
-
-error: aborting due to previous error
+   --> src/main.rs:4:36
+    |
+3   | / fn main() {
+4   | |     let f = File::open("hello.txt")?;
+    | |                                    ^ cannot use the `?` operator in a function that returns `()`
+5   | | }
+    | |_- this function should return `Result` or `Option` to accept `?`
+    |
+    = help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
+note: required by `from_residual`

 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `error-handling`
-
-To learn more, run the command again with --verbose.
+error: could not compile `error-handling` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/listing-10-05/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/listing-10-05/output.txt
@ -13,9 +13,5 @@ help: consider restricting type parameter `T`
 1 | fn largest<T: std::cmp::PartialOrd>(list: &[T]) -> T {
  |             ^^^^^^^^^^^^^^^^^^^^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0369`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/listing-10-07/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/listing-10-07/output.txt
@ -6,9 +6,5 @@ error[E0308]: mismatched types
 7 |     let wont_work = Point { x: 5, y: 4.0 };
  |                                      ^^^ expected integer, found floating-point number

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/listing-10-17/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/listing-10-17/output.txt
@ -11,9 +11,5 @@ error[E0597]: `x` does not live long enough
 10 |         println!("r: {}", r);
   |                           - borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0597`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/listing-10-21/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/listing-10-21/output.txt
@ -12,9 +12,5 @@ help: consider introducing a named lifetime parameter
 9 | fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
  |           ^^^^    ^^^^^^^     ^^^^^^^     ^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0106`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/listing-10-24/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/listing-10-24/output.txt
@ -10,9 +10,5 @@ error[E0597]: `string2` does not live long enough
 8 |     println!("The longest string is {}", result);
  |                                          ------ borrow later used here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0597`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch10-generic-types-traits-and-lifetimes/no-listing-07-fixing-listing-10-05/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/no-listing-07-fixing-listing-10-05/output.txt
@ -20,10 +20,6 @@ error[E0507]: cannot move out of a shared reference
  |         |move occurs because `item` has type `T`, which does not implement the `Copy` trait
  |         help: consider removing the `&`: `item`

-error: aborting due to 2 previous errors
-
 Some errors have detailed explanations: E0507, E0508.
 For more information about an error, try `rustc --explain E0507`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to 2 previous errors
--- a/listings/ch10-generic-types-traits-and-lifetimes/no-listing-09-unrelated-lifetime/output.txt
+++ b/listings/ch10-generic-types-traits-and-lifetimes/no-listing-09-unrelated-lifetime/output.txt
@ -9,9 +9,5 @@ error[E0515]: cannot return value referencing local variable `result`
   |     returns a value referencing data owned by the current function
   |     `result` is borrowed here

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0515`.
-error: could not compile `chapter10`
-
-To learn more, run the command again with --verbose.
+error: could not compile `chapter10` due to previous error
--- a/listings/ch11-writing-automated-tests/no-listing-11-ignore-a-test/output.txt
+++ b/listings/ch11-writing-automated-tests/no-listing-11-ignore-a-test/output.txt
@ -7,7 +7,7 @@ running 2 tests
 test expensive_test ... ignored
 test it_works ... ok

-test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 0.02s
+test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 0.00s

   Doc-tests adder

--- a/listings/ch12-an-io-project/listing-12-12/output.txt
+++ b/listings/ch12-an-io-project/listing-12-12/output.txt
@ -9,8 +9,7 @@ warning: unused `Result` that must be used
   = note: `#[warn(unused_must_use)]` on by default
   = note: this `Result` may be an `Err` variant, which should be handled

-warning: 1 warning emitted
-
+warning: `minigrep` (bin "minigrep") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.71s
     Running `target/debug/minigrep the poem.txt`
 Searching for the
--- a/listings/ch12-an-io-project/output-only-02-missing-lifetimes/output.txt
+++ b/listings/ch12-an-io-project/output-only-02-missing-lifetimes/output.txt
@ -12,9 +12,5 @@ help: consider introducing a named lifetime parameter
 28 | pub fn search<'a>(query: &'a str, contents: &'a str) -> Vec<&'a str> {
   |              ^^^^        ^^^^^^^            ^^^^^^^         ^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0106`.
-error: could not compile `minigrep`
-
-To learn more, run the command again with --verbose.
+error: could not compile `minigrep` due to previous error
--- a/listings/ch13-functional-features/listing-13-08/output.txt
+++ b/listings/ch13-functional-features/listing-13-08/output.txt
@ -9,9 +9,5 @@ error[E0308]: mismatched types
  |                             expected struct `String`, found integer
  |                             help: try using a conversion method: `5.to_string()`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `closure-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `closure-example` due to previous error
--- a/listings/ch13-functional-features/listing-13-17/output.txt
+++ b/listings/ch13-functional-features/listing-13-17/output.txt
@ -9,7 +9,6 @@ warning: unused `Map` that must be used
  = note: `#[warn(unused_must_use)]` on by default
  = note: iterators are lazy and do nothing unless consumed

-warning: 1 warning emitted
-
+warning: `iterators` (bin "iterators") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.47s
     Running `target/debug/iterators`
--- a/listings/ch13-functional-features/no-listing-02-functions-cant-capture/output.txt
+++ b/listings/ch13-functional-features/no-listing-02-functions-cant-capture/output.txt
@ -8,9 +8,5 @@ error[E0434]: can't capture dynamic environment in a fn item
  |
  = help: use the `|| { ... }` closure form instead

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0434`.
-error: could not compile `equal-to-x`
-
-To learn more, run the command again with --verbose.
+error: could not compile `equal-to-x` due to previous error
--- a/listings/ch13-functional-features/no-listing-03-move-closures/output.txt
+++ b/listings/ch13-functional-features/no-listing-03-move-closures/output.txt
@ -14,9 +14,5 @@ error[E0382]: borrow of moved value: `x`
 6 |     println!("can't use x here: {:?}", x);
  |                                        ^ value borrowed here after move

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `equal-to-x`
-
-To learn more, run the command again with --verbose.
+error: could not compile `equal-to-x` due to previous error
--- a/listings/ch15-smart-pointers/listing-15-03/output.txt
+++ b/listings/ch15-smart-pointers/listing-15-03/output.txt
@ -22,10 +22,6 @@ error[E0391]: cycle detected when computing drop-check constraints for `List`
  = note: ...which again requires computing drop-check constraints for `List`, completing the cycle
  = note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing }, value: List } }`

-error: aborting due to 2 previous errors
-
 Some errors have detailed explanations: E0072, E0391.
 For more information about an error, try `rustc --explain E0072`.
-error: could not compile `cons-list`
-
-To learn more, run the command again with --verbose.
+error: could not compile `cons-list` due to 2 previous errors
--- a/listings/ch15-smart-pointers/listing-15-09/output.txt
+++ b/listings/ch15-smart-pointers/listing-15-09/output.txt
@ -6,9 +6,5 @@ error[E0614]: type `MyBox<{integer}>` cannot be dereferenced
 14 |     assert_eq!(5, *y);
   |                   ^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0614`.
-error: could not compile `deref-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `deref-example` due to previous error
--- a/listings/ch15-smart-pointers/listing-15-15/output.txt
+++ b/listings/ch15-smart-pointers/listing-15-15/output.txt
@ -9,9 +9,5 @@ error[E0040]: explicit use of destructor method
   |     | explicit destructor calls not allowed
   |     help: consider using `drop` function: `drop(c)`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0040`.
-error: could not compile `drop-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `drop-example` due to previous error
--- a/listings/ch15-smart-pointers/listing-15-17/output.txt
+++ b/listings/ch15-smart-pointers/listing-15-17/output.txt
@ -10,9 +10,5 @@ error[E0382]: use of moved value: `a`
 11 |     let c = Cons(4, Box::new(a));
   |                              ^ value used here after move

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `cons-list`
-
-To learn more, run the command again with --verbose.
+error: could not compile `cons-list` due to previous error
--- a/listings/ch15-smart-pointers/listing-15-21/output.txt
+++ b/listings/ch15-smart-pointers/listing-15-21/output.txt
@ -9,11 +9,7 @@ error[E0596]: cannot borrow `self.sent_messages` as mutable, as it is behind a `
 58 |             self.sent_messages.push(String::from(message));
   |             ^^^^^^^^^^^^^^^^^^ `self` is a `&` reference, so the data it refers to cannot be borrowed as mutable

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0596`.
-error: could not compile `limit-tracker`
-
-To learn more, run the command again with --verbose.
+error: could not compile `limit-tracker` due to previous error
 warning: build failed, waiting for other jobs to finish...
 error: build failed
--- a/listings/ch15-smart-pointers/no-listing-01-cant-borrow-immutable-as-mutable/output.txt
+++ b/listings/ch15-smart-pointers/no-listing-01-cant-borrow-immutable-as-mutable/output.txt
@ -8,9 +8,5 @@ error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
 3 |     let y = &mut x;
  |             ^^^^^^ cannot borrow as mutable

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0596`.
-error: could not compile `borrowing`
-
-To learn more, run the command again with --verbose.
+error: could not compile `borrowing` due to previous error
--- a/listings/ch15-smart-pointers/output-only-01-comparing-to-reference/output.txt
+++ b/listings/ch15-smart-pointers/output-only-01-comparing-to-reference/output.txt
@ -9,9 +9,5 @@ error[E0277]: can't compare `{integer}` with `&{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)

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `deref-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `deref-example` due to previous error
--- a/listings/ch16-fearless-concurrency/listing-16-03/output.txt
+++ b/listings/ch16-fearless-concurrency/listing-16-03/output.txt
@ -21,9 +21,5 @@ help: to force the closure to take ownership of `v` (and any other referenced va
 6 |     let handle = thread::spawn(move || {
  |                                ^^^^^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0373`.
-error: could not compile `threads`
-
-To learn more, run the command again with --verbose.
+error: could not compile `threads` due to previous error
--- a/listings/ch16-fearless-concurrency/listing-16-09/output.txt
+++ b/listings/ch16-fearless-concurrency/listing-16-09/output.txt
@ -10,9 +10,5 @@ error[E0382]: borrow of moved value: `val`
 10 |         println!("val is {}", val);
   |                               ^^^ value borrowed here after move

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `message-passing`
-
-To learn more, run the command again with --verbose.
+error: could not compile `message-passing` due to previous error
--- a/listings/ch16-fearless-concurrency/listing-16-13/output.txt
+++ b/listings/ch16-fearless-concurrency/listing-16-13/output.txt
@ -11,9 +11,5 @@ error[E0382]: use of moved value: `counter`
 10 |             let mut num = counter.lock().unwrap();
   |                           ------- use occurs due to use in closure

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `shared-state`
-
-To learn more, run the command again with --verbose.
+error: could not compile `shared-state` due to previous error
--- a/listings/ch16-fearless-concurrency/listing-16-14/output.txt
+++ b/listings/ch16-fearless-concurrency/listing-16-14/output.txt
@ -16,9 +16,5 @@ error[E0277]: `Rc<Mutex<i32>>` cannot be sent between threads safely
    = help: within `[closure@src/main.rs:11:36: 15:10]`, the trait `Send` is not implemented for `Rc<Mutex<i32>>`
    = note: required because it appears within the type `[closure@src/main.rs:11:36: 15:10]`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `shared-state`
-
-To learn more, run the command again with --verbose.
+error: could not compile `shared-state` due to previous error
--- a/listings/ch16-fearless-concurrency/output-only-01-move-drop/output.txt
+++ b/listings/ch16-fearless-concurrency/output-only-01-move-drop/output.txt
@ -14,9 +14,5 @@ error[E0382]: use of moved value: `v`
 10 |     drop(v); // oh no!
   |          ^ value used here after move

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `threads`
-
-To learn more, run the command again with --verbose.
+error: could not compile `threads` due to previous error
--- a/listings/ch17-oop/listing-17-10/output.txt
+++ b/listings/ch17-oop/listing-17-10/output.txt
@ -8,9 +8,5 @@ error[E0277]: the trait bound `String: Draw` is not satisfied
  |
  = note: required for the cast to the object type `dyn Draw`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `gui`
-
-To learn more, run the command again with --verbose.
+error: could not compile `gui` due to previous error
--- a/listings/ch17-oop/no-listing-01-trait-object-of-clone/output.txt
+++ b/listings/ch17-oop/no-listing-01-trait-object-of-clone/output.txt
@ -1,17 +1,13 @@
 $ cargo build
   Compiling gui v0.1.0 (file:///projects/gui)
 error[E0038]: the trait `Clone` cannot be made into an object
- --> src/lib.rs:2:21
+ --> src/lib.rs:2:29
  |
 2 |     pub components: Vec<Box<dyn Clone>>,
-  |                     ^^^^^^^^^^^^^^^^^^^ `Clone` cannot be made into an object
+  |                             ^^^^^^^^^ `Clone` cannot be made into an object
  |
  = note: the trait cannot be made into an object because it requires `Self: Sized`
  = note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0038`.
-error: could not compile `gui`
-
-To learn more, run the command again with --verbose.
+error: could not compile `gui` due to previous error
--- a/listings/ch18-patterns-and-matching/listing-18-05/output.txt
+++ b/listings/ch18-patterns-and-matching/listing-18-05/output.txt
@ -11,9 +11,5 @@ error[E0308]: mismatched types
  = note: expected tuple `({integer}, {integer}, {integer})`
             found tuple `(_, _)`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0308`.
-error: could not compile `patterns`
-
-To learn more, run the command again with --verbose.
+error: could not compile `patterns` due to previous error
--- a/listings/ch18-patterns-and-matching/listing-18-08/output.txt
+++ b/listings/ch18-patterns-and-matching/listing-18-08/output.txt
@ -14,9 +14,5 @@ help: you might want to use `if let` to ignore the variant that isn't matched
 3   |     if let Some(x) = some_option_value { /* */ }
    |

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0005`.
-error: could not compile `patterns`
-
-To learn more, run the command again with --verbose.
+error: could not compile `patterns` due to previous error
--- a/listings/ch18-patterns-and-matching/listing-18-10/output.txt
+++ b/listings/ch18-patterns-and-matching/listing-18-10/output.txt
@ -12,8 +12,7 @@ warning: irrefutable `if let` pattern
  = note: this pattern will always match, so the `if let` is useless
  = help: consider replacing the `if let` with a `let`

-warning: 1 warning emitted
-
+warning: `patterns` (bin "patterns") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.39s
     Running `target/debug/patterns`
 5
--- a/listings/ch18-patterns-and-matching/listing-18-25/output.txt
+++ b/listings/ch18-patterns-and-matching/listing-18-25/output.txt
@ -8,8 +8,4 @@ error: `..` can only be used once per tuple pattern
  |          |
  |          previously used here

-error: aborting due to previous error
-
-error: could not compile `patterns`
-
-To learn more, run the command again with --verbose.
+error: could not compile `patterns` due to previous error
--- a/listings/ch19-advanced-features/listing-19-05/output.txt
+++ b/listings/ch19-advanced-features/listing-19-05/output.txt
@ -13,9 +13,5 @@ error[E0499]: cannot borrow `*slice` as mutable more than once at a time
  |     |     first mutable borrow occurs here
  |     returning this value requires that `*slice` is borrowed for `'1`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0499`.
-error: could not compile `unsafe-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `unsafe-example` due to previous error
--- a/listings/ch19-advanced-features/listing-19-20/output.txt
+++ b/listings/ch19-advanced-features/listing-19-20/output.txt
@ -3,17 +3,15 @@ $ cargo run
 error[E0283]: type annotations needed
  --> src/main.rs:20:43
   |
-2  |     fn baby_name() -> String;
-   |     ------------------------- required by `Animal::baby_name`
-...
 20 |     println!("A baby dog is called a {}", Animal::baby_name());
   |                                           ^^^^^^^^^^^^^^^^^ cannot infer type
   |
   = note: cannot satisfy `_: Animal`
-
-error: aborting due to previous error
+note: required by `Animal::baby_name`
+  --> src/main.rs:2:5
+   |
+2  |     fn baby_name() -> String;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^

 For more information about this error, try `rustc --explain E0283`.
-error: could not compile `traits-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `traits-example` due to previous error
--- a/listings/ch19-advanced-features/no-listing-02-impl-outlineprint-for-point/output.txt
+++ b/listings/ch19-advanced-features/no-listing-02-impl-outlineprint-for-point/output.txt
@ -12,9 +12,5 @@ error[E0277]: `Point` doesn't implement `std::fmt::Display`
   = help: the trait `std::fmt::Display` is not implemented for `Point`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0277`.
-error: could not compile `traits-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `traits-example` due to previous error
--- a/listings/ch19-advanced-features/no-listing-18-returns-closure/output.txt
+++ b/listings/ch19-advanced-features/no-listing-18-returns-closure/output.txt
@ -12,9 +12,5 @@ help: use `impl Fn(i32) -> i32` as the return type, as all return paths are of t
 1 | fn returns_closure() -> impl Fn(i32) -> i32 {
  |                         ^^^^^^^^^^^^^^^^^^^

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0746`.
-error: could not compile `functions-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `functions-example` due to previous error
--- a/listings/ch19-advanced-features/output-only-01-missing-unsafe/output.txt
+++ b/listings/ch19-advanced-features/output-only-01-missing-unsafe/output.txt
@ -8,9 +8,5 @@ error[E0133]: call to unsafe function is unsafe and requires unsafe function or
  |
  = note: consult the function's documentation for information on how to avoid undefined behavior

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0133`.
-error: could not compile `unsafe-example`
-
-To learn more, run the command again with --verbose.
+error: could not compile `unsafe-example` due to previous error
--- a/listings/ch20-web-server/listing-20-12/output.txt
+++ b/listings/ch20-web-server/listing-20-12/output.txt
@ -6,9 +6,5 @@ error[E0433]: failed to resolve: use of undeclared type `ThreadPool`
 10 |     let pool = ThreadPool::new(4);
   |                ^^^^^^^^^^ use of undeclared type `ThreadPool`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0433`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to previous error
--- a/listings/ch20-web-server/listing-20-17/output.txt
+++ b/listings/ch20-web-server/listing-20-17/output.txt
@ -9,9 +9,5 @@ error[E0382]: use of moved value: `receiver`
 27 |             workers.push(Worker::new(id, receiver));
   |                                          ^^^^^^^^ value moved here, in previous iteration of loop

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0382`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to previous error
--- a/listings/ch20-web-server/listing-20-22/output.txt
+++ b/listings/ch20-web-server/listing-20-22/output.txt
@ -6,9 +6,5 @@ error[E0507]: cannot move out of `worker.thread` which is behind a mutable refer
 52 |             worker.thread.join().unwrap();
   |             ^^^^^^^^^^^^^ move occurs because `worker.thread` has type `JoinHandle<()>`, which does not implement the `Copy` trait

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0507`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to previous error
--- a/listings/ch20-web-server/no-listing-01-define-threadpool-struct/output.txt
+++ b/listings/ch20-web-server/no-listing-01-define-threadpool-struct/output.txt
@ -6,9 +6,5 @@ error[E0599]: no function or associated item named `new` found for struct `Threa
 11 |     let pool = ThreadPool::new(4);
   |                            ^^^ function or associated item not found in `ThreadPool`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0599`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to previous error
--- a/listings/ch20-web-server/no-listing-02-impl-threadpool-new/output.txt
+++ b/listings/ch20-web-server/no-listing-02-impl-threadpool-new/output.txt
@ -6,9 +6,5 @@ error[E0599]: no method named `execute` found for struct `ThreadPool` in the cur
 16 |         pool.execute(|| {
   |              ^^^^^^^ method not found in `ThreadPool`

-error: aborting due to previous error
-
 For more information about this error, try `rustc --explain E0599`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to previous error
--- a/listings/ch20-web-server/no-listing-04-update-worker-definition/output.txt
+++ b/listings/ch20-web-server/no-listing-04-update-worker-definition/output.txt
@ -18,10 +18,6 @@ error[E0308]: mismatched types
   = note: expected enum `Option<JoinHandle<()>>`
            found struct `JoinHandle<_>`

-error: aborting due to 2 previous errors
-
 Some errors have detailed explanations: E0308, E0599.
 For more information about an error, try `rustc --explain E0308`.
-error: could not compile `hello`
-
-To learn more, run the command again with --verbose.
+error: could not compile `hello` due to 2 previous errors
--- a/2
+++ b/2
@ -1 +1 @@
-1.54
+1.55
--- a/src/title-page.md
+++ b/src/title-page.md
@ -2,7 +2,7 @@

 *by Steve Klabnik and Carol Nichols, with contributions from the Rust Community*

-This version of the text assumes you’re using Rust 1.54 or later with
+This version of the text assumes you’re using Rust 1.55 or later with
 `edition="2018"` in *Cargo.toml* of all projects to use Rust 2018 Edition
 idioms. See the [“Installation” section of Chapter 1][install]<!-- ignore -->
 to install or update Rust, and see the new [Appendix E][editions]<!-- ignore
 @ -1 +1 @@
 .54
 .55