[INFO] cloning repository https://github.com/br1code/rust-ownership
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/br1code/rust-ownership" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbr1code%2Frust-ownership", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbr1code%2Frust-ownership'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bb687a123c246932157b72d9134b507474d1cc6b
[INFO] checking br1code/rust-ownership/bb687a123c246932157b72d9134b507474d1cc6b against master#f609b7e0586f81fefb3523e3e17adf779ac416be for pr-129466-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbr1code%2Frust-ownership" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/br1code/rust-ownership on toolchain f609b7e0586f81fefb3523e3e17adf779ac416be
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/br1code/rust-ownership
[INFO] finished tweaking git repo https://github.com/br1code/rust-ownership
[INFO] tweaked toml for git repo https://github.com/br1code/rust-ownership written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/br1code/rust-ownership already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ac06fb0c11c1e32bf254cd52f38f112da98b19042a7422a73cf6f9f7180cdf54
[INFO] running `Command { std: "docker" "start" "-a" "ac06fb0c11c1e32bf254cd52f38f112da98b19042a7422a73cf6f9f7180cdf54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ac06fb0c11c1e32bf254cd52f38f112da98b19042a7422a73cf6f9f7180cdf54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac06fb0c11c1e32bf254cd52f38f112da98b19042a7422a73cf6f9f7180cdf54", kill_on_drop: false }`
[INFO] [stdout] ac06fb0c11c1e32bf254cd52f38f112da98b19042a7422a73cf6f9f7180cdf54
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:6252d7ea7fb8caaf7af6d800c5fb250a9cd862b9a7f9508afb3c54fa7fe1102e" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4c03d78697308230ec0fd1b88e12bcff5a7cff04c86da3eac660670af0cea0fb
[INFO] running `Command { std: "docker" "start" "-a" "4c03d78697308230ec0fd1b88e12bcff5a7cff04c86da3eac660670af0cea0fb", kill_on_drop: false }`
[INFO] [stderr]     Checking rust-ownership v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]    --> src/references_and_borrowing.rs:141:16
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn dangle() -> &String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |                ^ expected named lifetime parameter
[INFO] [stdout]     |
[INFO] [stdout]     = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn dangle() -> &'static String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] help: instead, you are more likely to want to return an owned value
[INFO] [stdout]     |
[INFO] [stdout] 141 - fn dangle() -> &String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout] 141 + fn dangle() -> String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]    --> src/references_and_borrowing.rs:141:16
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn dangle() -> &String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |                ^ expected named lifetime parameter
[INFO] [stdout]     |
[INFO] [stdout]     = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn dangle() -> &'static String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] help: instead, you are more likely to want to return an owned value
[INFO] [stdout]     |
[INFO] [stdout] 141 - fn dangle() -> &String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout] 141 + fn dangle() -> String { // error[E0106]: missing lifetime specifier, help: consider giving it a 'static lifetime: `&'static`
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]    --> src/slice_type.rs:120:40
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn first_word_signature(s: &String) -> &str {}
[INFO] [stdout]     |    --------------------                ^^^^ expected `&str`, found `()`
[INFO] [stdout]     |    |
[INFO] [stdout]     |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]    --> src/slice_type.rs:120:40
[INFO] [stdout]     |
[INFO] [stdout] 120 | fn first_word_signature(s: &String) -> &str {}
[INFO] [stdout]     |    --------------------                ^^^^ expected `&str`, found `()`
[INFO] [stdout]     |    |
[INFO] [stdout]     |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]    --> src/slice_type.rs:123:44
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn first_word_better_signature(s: &str) -> &str {}
[INFO] [stdout]     |    ---------------------------             ^^^^ expected `&str`, found `()`
[INFO] [stdout]     |    |
[INFO] [stdout]     |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]     |
[INFO] [stdout] help: consider returning the local binding `s`
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn first_word_better_signature(s: &str) -> &str { s }
[INFO] [stdout]     |                                                   +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]    --> src/slice_type.rs:123:44
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn first_word_better_signature(s: &str) -> &str {}
[INFO] [stdout]     |    ---------------------------             ^^^^ expected `&str`, found `()`
[INFO] [stdout]     |    |
[INFO] [stdout]     |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout]     |
[INFO] [stdout] help: consider returning the local binding `s`
[INFO] [stdout]     |
[INFO] [stdout] 123 | fn first_word_better_signature(s: &str) -> &str { s }
[INFO] [stdout]     |                                                   +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/slice_type.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = &s[0..5]; // hello
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/slice_type.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = &s[0..5]; // hello
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/slice_type.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let world = &s[6..11]; // world
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]   --> src/slice_type.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let world = &s[6..11]; // world
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let slice = &s[0..2];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let slice = &s[0..2];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let slice = &s[..2];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let slice = &s[..2];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let slice = &s[3..len];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let slice = &s[3..len];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let slice = &s[3..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let slice = &s[3..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let slice = &s[0..len];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let slice = &s[0..len];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let slice = &s[..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slice_type.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let slice = &s[..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/slice_type.rs:85:5
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let word = first_word(&s); // -- immutable borrow occurs here
[INFO] [stdout]    |                           -- immutable borrow occurs here
[INFO] [stdout] 84 |
[INFO] [stdout] 85 |     s.clear(); // error! error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]    |     ^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 88 |     println!("the first word is: {}", word); // ---- immutable borrow later used here
[INFO] [stdout]    |                                       ---- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/slice_type.rs:85:5
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let word = first_word(&s); // -- immutable borrow occurs here
[INFO] [stdout]    |                           -- immutable borrow occurs here
[INFO] [stdout] 84 |
[INFO] [stdout] 85 |     s.clear(); // error! error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]    |     ^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 88 |     println!("the first word is: {}", word); // ---- immutable borrow later used here
[INFO] [stdout]    |                                       ---- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `mutable` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/slice_type.rs:97:5
[INFO] [stdout]     |
[INFO] [stdout] 95  |     let immutable_reference = &mutable; // -------- immutable borrow occurs here
[INFO] [stdout]     |                               -------- immutable borrow occurs here
[INFO] [stdout] 96  |
[INFO] [stdout] 97  |     mutable.clear(); // here we try to modify the mutable, but we can't because we already have an immutable reference of the same variable
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 101 |     println!("{}", immutable_reference); // if this wasn't here, the code will be okay.
[INFO] [stdout]     |                    ------------------- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `mutable` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/slice_type.rs:97:5
[INFO] [stdout]     |
[INFO] [stdout] 95  |     let immutable_reference = &mutable; // -------- immutable borrow occurs here
[INFO] [stdout]     |                               -------- immutable borrow occurs here
[INFO] [stdout] 96  |
[INFO] [stdout] 97  |     mutable.clear(); // here we try to modify the mutable, but we can't because we already have an immutable reference of the same variable
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 101 |     println!("{}", immutable_reference); // if this wasn't here, the code will be okay.
[INFO] [stdout]     |                    ------------------- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/slice_type.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |     let s = "Hello, world!";
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     let word = first_word_better_signature(&my_string[..]);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/slice_type.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |     let s = "Hello, world!";
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     let word = first_word_better_signature(&my_string[..]);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:136:9
[INFO] [stdout]     |
[INFO] [stdout] 136 |     let word = first_word_better_signature(&my_string_literal[..]);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:136:9
[INFO] [stdout]     |
[INFO] [stdout] 136 |     let word = first_word_better_signature(&my_string_literal[..]);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:140:9
[INFO] [stdout]     |
[INFO] [stdout] 140 |     let word = first_word_better_signature(my_string_literal);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/slice_type.rs:146:9
[INFO] [stdout]     |
[INFO] [stdout] 146 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]    --> src/slice_type.rs:140:9
[INFO] [stdout]     |
[INFO] [stdout] 140 |     let word = first_word_better_signature(my_string_literal);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/slice_type.rs:153:9
[INFO] [stdout]     |
[INFO] [stdout] 153 |     let slice = &a[1..3]; // [2, 3]
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/slice_type.rs:146:9
[INFO] [stdout]     |
[INFO] [stdout] 146 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/slice_type.rs:153:9
[INFO] [stdout]     |
[INFO] [stdout] 153 |     let slice = &a[1..3]; // [2, 3]
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/references_and_borrowing.rs:41:11
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/references_and_borrowing.rs:41:11
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0499]: cannot borrow `s` as mutable more than once at a time
[INFO] [stdout]   --> src/references_and_borrowing.rs:68:14
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let r1 = &mut s;
[INFO] [stdout]    |              ------ first mutable borrow occurs here
[INFO] [stdout] 68 |     let r2 = &mut s; // error[E0499]: cannot borrow `s` as mutable more than once at a time
[INFO] [stdout]    |              ^^^^^^ second mutable borrow occurs here
[INFO] [stdout] 69 |
[INFO] [stdout] 70 |     println!("{}, {}", r1, r2);
[INFO] [stdout]    |                        -- first borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references_and_borrowing.rs:91:13
[INFO] [stdout]    |
[INFO] [stdout] 91 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0499]: cannot borrow `s` as mutable more than once at a time
[INFO] [stdout]   --> src/references_and_borrowing.rs:68:14
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let r1 = &mut s;
[INFO] [stdout]    |              ------ first mutable borrow occurs here
[INFO] [stdout] 68 |     let r2 = &mut s; // error[E0499]: cannot borrow `s` as mutable more than once at a time
[INFO] [stdout]    |              ^^^^^^ second mutable borrow occurs here
[INFO] [stdout] 69 |
[INFO] [stdout] 70 |     println!("{}, {}", r1, r2);
[INFO] [stdout]    |                        -- first borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/references_and_borrowing.rs:94:9
[INFO] [stdout]    |
[INFO] [stdout] 94 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references_and_borrowing.rs:91:13
[INFO] [stdout]    |
[INFO] [stdout] 91 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/references_and_borrowing.rs:94:9
[INFO] [stdout]    |
[INFO] [stdout] 94 |     let r2 = &mut s;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/references_and_borrowing.rs:103:14
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let r1 = &s; // no problem
[INFO] [stdout]     |              -- immutable borrow occurs here
[INFO] [stdout] 102 |     let r2 = &s; // no problem
[INFO] [stdout] 103 |     let r3 = &mut s; // BIG PROBLEM
[INFO] [stdout]     |              ^^^^^^ mutable borrow occurs here
[INFO] [stdout] 104 |
[INFO] [stdout] 105 |     println!("{}, {}, and {}", r1, r2, r3);
[INFO] [stdout]     |                                -- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `s` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/references_and_borrowing.rs:103:14
[INFO] [stdout]     |
[INFO] [stdout] 101 |     let r1 = &s; // no problem
[INFO] [stdout]     |              -- immutable borrow occurs here
[INFO] [stdout] 102 |     let r2 = &s; // no problem
[INFO] [stdout] 103 |     let r3 = &mut s; // BIG PROBLEM
[INFO] [stdout]     |              ^^^^^^ mutable borrow occurs here
[INFO] [stdout] 104 |
[INFO] [stdout] 105 |     println!("{}, {}, and {}", r1, r2, r3);
[INFO] [stdout]     |                                -- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reference_to_nothing`
[INFO] [stdout]    --> src/references_and_borrowing.rs:137:9
[INFO] [stdout]     |
[INFO] [stdout] 137 |     let reference_to_nothing = dangle();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return reference to local variable `s`
[INFO] [stdout]    --> src/references_and_borrowing.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     &s // we return a reference to the String, s
[INFO] [stdout]     |     ^^ returns a reference to data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reference_to_nothing`
[INFO] [stdout]    --> src/references_and_borrowing.rs:137:9
[INFO] [stdout]     |
[INFO] [stdout] 137 |     let reference_to_nothing = dangle();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reference_to_nothing`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let s = "hello"; // s is valid from this point forward
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = String::from("hello");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return reference to local variable `s`
[INFO] [stdout]    --> src/references_and_borrowing.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     &s // we return a reference to the String, s
[INFO] [stdout]     |     ^^ returns a reference to data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let s = "hello"; // s is valid from this point forward
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = String::from("hello");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     let s = String::from("hello"); // s is valid from this point forward
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/main.rs:115:9
[INFO] [stdout]     |
[INFO] [stdout] 115 |     let y = x;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]    --> src/main.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 125 |     let s2 = s1;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/main.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     let s = String::from("hello"); // s is valid from this point forward
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]    --> src/main.rs:152:9
[INFO] [stdout]     |
[INFO] [stdout] 152 |     let s2 = s1;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/main.rs:115:9
[INFO] [stdout]     |
[INFO] [stdout] 115 |     let y = x;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]    --> src/main.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 125 |     let s2 = s1;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]    --> src/main.rs:152:9
[INFO] [stdout]     |
[INFO] [stdout] 152 |     let s2 = s1;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0382]: borrow of moved value: `s1`
[INFO] [stdout]    --> src/main.rs:154:28
[INFO] [stdout]     |
[INFO] [stdout] 151 |     let s1 = String::from("hello");
[INFO] [stdout]     |         -- move occurs because `s1` has type `String`, which does not implement the `Copy` trait
[INFO] [stdout] 152 |     let s2 = s1;
[INFO] [stdout]     |              -- value moved here
[INFO] [stdout] 153 |
[INFO] [stdout] 154 |     println!("{}, world!", s1);
[INFO] [stdout]     |                            ^^ value borrowed here after move
[INFO] [stdout]     |
[INFO] [stdout]     = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] help: consider cloning the value if the performance cost is acceptable
[INFO] [stdout]     |
[INFO] [stdout] 152 |     let s2 = s1.clone();
[INFO] [stdout]     |                ++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0382]: borrow of moved value: `s1`
[INFO] [stdout]    --> src/main.rs:154:28
[INFO] [stdout]     |
[INFO] [stdout] 151 |     let s1 = String::from("hello");
[INFO] [stdout]     |         -- move occurs because `s1` has type `String`, which does not implement the `Copy` trait
[INFO] [stdout] 152 |     let s2 = s1;
[INFO] [stdout]     |              -- value moved here
[INFO] [stdout] 153 |
[INFO] [stdout] 154 |     println!("{}, world!", s1);
[INFO] [stdout]     |                            ^^ value borrowed here after move
[INFO] [stdout]     |
[INFO] [stdout]     = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] help: consider cloning the value if the performance cost is acceptable
[INFO] [stdout]     |
[INFO] [stdout] 152 |     let s2 = s1.clone();
[INFO] [stdout]     |                ++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]    --> src/main.rs:246:9
[INFO] [stdout]     |
[INFO] [stdout] 246 |     let s1 = gives_ownership();         // gives_ownership moves its return value into s1
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]    --> src/main.rs:250:9
[INFO] [stdout]     |
[INFO] [stdout] 250 |     let s3 = takes_and_gives_back(s2);  // s2 is moved into takes_and_gives_back, which also moves its return value into s3
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]    --> src/main.rs:246:9
[INFO] [stdout]     |
[INFO] [stdout] 246 |     let s1 = gives_ownership();         // gives_ownership moves its return value into s1
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]    --> src/main.rs:250:9
[INFO] [stdout]     |
[INFO] [stdout] 250 |     let s3 = takes_and_gives_back(s2);  // s2 is moved into takes_and_gives_back, which also moves its return value into s3
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 9 previous errors; 26 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0106, E0308, E0382, E0499, E0502, E0515.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 9 previous errors; 26 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0106, E0308, E0382, E0499, E0502, E0515.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-ownership` (bin "rust-ownership") due to 10 previous errors; 26 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rust-ownership` (bin "rust-ownership" test) due to 10 previous errors; 26 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "4c03d78697308230ec0fd1b88e12bcff5a7cff04c86da3eac660670af0cea0fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4c03d78697308230ec0fd1b88e12bcff5a7cff04c86da3eac660670af0cea0fb", kill_on_drop: false }`
[INFO] [stdout] 4c03d78697308230ec0fd1b88e12bcff5a7cff04c86da3eac660670af0cea0fb