[INFO] cloning repository https://github.com/masa-matt/rust-tutrial
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/masa-matt/rust-tutrial" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmasa-matt%2Frust-tutrial", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmasa-matt%2Frust-tutrial'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f572f11c89d483c1e75e90de7350b967c35b7b45
[INFO] checking masa-matt/rust-tutrial against try#b4c55082edd8dec08ce8af276d7054d9c4db20c4 for pr-147984
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmasa-matt%2Frust-tutrial" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/masa-matt/rust-tutrial
[INFO] finished tweaking git repo https://github.com/masa-matt/rust-tutrial
[INFO] tweaked toml for git repo https://github.com/masa-matt/rust-tutrial written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/masa-matt/rust-tutrial on toolchain b4c55082edd8dec08ce8af276d7054d9c4db20c4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b4c55082edd8dec08ce8af276d7054d9c4db20c4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/masa-matt/rust-tutrial 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" "+b4c55082edd8dec08ce8af276d7054d9c4db20c4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: virtual workspace defaulting to `resolver = "1"` despite one or more workspace members being on edition 2021 which implies `resolver = "2"`
[INFO] [stderr]   |
[INFO] [stderr]   = note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
[INFO] [stderr]   = note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
[INFO] [stderr]   = note: for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rug v1.19.0
[INFO] [stderr]   Downloaded gmp-mpfr-sys v1.5.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+b4c55082edd8dec08ce8af276d7054d9c4db20c4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 836a9aefb62ba8d3ddbe924b0008677e52d693c18ebfbc8993bb9ddfff030926
[INFO] running `Command { std: "docker" "start" "-a" "836a9aefb62ba8d3ddbe924b0008677e52d693c18ebfbc8993bb9ddfff030926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "836a9aefb62ba8d3ddbe924b0008677e52d693c18ebfbc8993bb9ddfff030926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "836a9aefb62ba8d3ddbe924b0008677e52d693c18ebfbc8993bb9ddfff030926", kill_on_drop: false }`
[INFO] [stdout] 836a9aefb62ba8d3ddbe924b0008677e52d693c18ebfbc8993bb9ddfff030926
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+b4c55082edd8dec08ce8af276d7054d9c4db20c4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5a876396e64a71b243544dcd119816b8f5595c2c418ced61e39dca6082579b01
[INFO] running `Command { std: "docker" "start" "-a" "5a876396e64a71b243544dcd119816b8f5595c2c418ced61e39dca6082579b01", kill_on_drop: false }`
[INFO] [stderr] warning: virtual workspace defaulting to `resolver = "1"` despite one or more workspace members being on edition 2021 which implies `resolver = "2"`
[INFO] [stderr]   |
[INFO] [stderr]   = note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
[INFO] [stderr]   = note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
[INFO] [stderr]   = note: for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions
[INFO] [stderr]    Compiling libc v0.2.139
[INFO] [stderr]    Compiling gmp-mpfr-sys v1.5.0
[INFO] [stderr]    Compiling rug v1.19.0
[INFO] [stderr]     Checking ch11-03-test-organization v0.1.0 (/opt/rustwide/workdir/ch11/ch11-03-test-organization)
[INFO] [stderr]     Checking ch09-02-recoverable-errors-with-result v0.1.0 (/opt/rustwide/workdir/ch09/ch09-02-recoverable-errors-with-result)
[INFO] [stderr]     Checking ch04-02-references-and-borrowing v0.1.0 (/opt/rustwide/workdir/ch04/ch04-02-references-and-borrowing)
[INFO] [stderr]     Checking ch10-01-syntax v0.1.0 (/opt/rustwide/workdir/ch10/ch10-01-syntax)
[INFO] [stderr]     Checking variables v0.1.0 (/opt/rustwide/workdir/ch03/ch03-01-variables-and-mutability)
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:68:16
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn dangle() -> &String {
[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] 68 | fn dangle() -> &'static String {
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] help: instead, you are more likely to want to return an owned value
[INFO] [stdout]    |
[INFO] [stdout] 68 - fn dangle() -> &String {
[INFO] [stdout] 68 + fn dangle() -> String {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:29:11
[INFO] [stdout]    |
[INFO] [stdout] 29 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let mut s2 = String::from("hello");
[INFO] [stdout]    |         ----^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     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: `r1`
[INFO] [stdout]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:50:13
[INFO] [stdout]    |
[INFO] [stdout] 50 |         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]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     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]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let r1 = &s2; // no problem
[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]   --> ch04/ch04-02-references-and-borrowing/src/main.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let r2 = &s2; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ch04-02-references-and-borrowing` (bin "ch04-02-references-and-borrowing" test) due to 1 previous error; 7 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let f = match f {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `greeting_file`
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let greeting_file = match greeting_file_result {
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greeting_file`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `type_result` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:19:4
[INFO] [stdout]    |
[INFO] [stdout] 19 | fn type_result() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `error_handling` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn error_handling() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `Option_i32` should have an upper camel case name
[INFO] [stdout]    --> ch10/ch10-01-syntax/src/main.rs:130:10
[INFO] [stdout]     |
[INFO] [stdout] 130 |     enum Option_i32 {
[INFO] [stdout]     |          ^^^^^^^^^^ help: convert the identifier to upper camel case: `OptionI32`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `error_unwrap` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 | fn error_unwrap() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `Option_f64` should have an upper camel case name
[INFO] [stdout]    --> ch10/ch10-01-syntax/src/main.rs:135:10
[INFO] [stdout]     |
[INFO] [stdout] 135 |     enum Option_f64 {
[INFO] [stdout]     |          ^^^^^^^^^^ help: convert the identifier to upper camel case: `OptionF64`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `error_expected` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:51:4
[INFO] [stdout]    |
[INFO] [stdout] 51 | fn error_expected() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `read_username_from_file` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `error_shortcut` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn error_shortcut() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `error_shortcut_shorter` is never used
[INFO] [stdout]   --> ch09/ch09-02-recoverable-errors-with-result/src/main.rs:78:4
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn error_shortcut_shorter() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]   --> ch10/ch10-01-syntax/src/main.rs:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let integer = Point { x: 5, y: 10 };
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]   --> ch10/ch10-01-syntax/src/main.rs:79:9
[INFO] [stdout]    |
[INFO] [stdout] 79 |     let float = Point { x: 1.0, y: 4.0 };
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `wont_work`
[INFO] [stdout]   --> ch10/ch10-01-syntax/src/main.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let wont_work = Point { x: 5, y: 4.0 };
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_wont_work`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> ch10/ch10-01-syntax/src/main.rs:141:13
[INFO] [stdout]     |
[INFO] [stdout] 141 |         let integer = Option_i32::Some(5);
[INFO] [stdout]     |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `float`
[INFO] [stdout]    --> ch10/ch10-01-syntax/src/main.rs:142:13
[INFO] [stdout]     |
[INFO] [stdout] 142 |         let float = Option_f64::Some(5.0);
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_float`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `monomorphized_code` is never used
[INFO] [stdout]    --> ch10/ch10-01-syntax/src/main.rs:129:4
[INFO] [stdout]     |
[INFO] [stdout] 129 | fn monomorphized_code() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "5a876396e64a71b243544dcd119816b8f5595c2c418ced61e39dca6082579b01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a876396e64a71b243544dcd119816b8f5595c2c418ced61e39dca6082579b01", kill_on_drop: false }`
[INFO] [stdout] 5a876396e64a71b243544dcd119816b8f5595c2c418ced61e39dca6082579b01