[INFO] cloning repository https://github.com/jfeldman325/Rust-Learning-Examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jfeldman325/Rust-Learning-Examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjfeldman325%2FRust-Learning-Examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjfeldman325%2FRust-Learning-Examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b32ce13aa45e32e6b5473a7ae44a9897c30e6af0
[INFO] checking jfeldman325/Rust-Learning-Examples against master#f82664191d0e8764b7435b9d72eb0e366b8b1464 for pr-83354
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjfeldman325%2FRust-Learning-Examples" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jfeldman325/Rust-Learning-Examples on toolchain f82664191d0e8764b7435b9d72eb0e366b8b1464
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jfeldman325/Rust-Learning-Examples
[INFO] finished tweaking git repo https://github.com/jfeldman325/Rust-Learning-Examples
[INFO] tweaked toml for git repo https://github.com/jfeldman325/Rust-Learning-Examples written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/jfeldman325/Rust-Learning-Examples already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-3/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 950ea8c9536723c82d9a5a2bb3d8f408279ef1558344a02596fb678a373641b2
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "950ea8c9536723c82d9a5a2bb3d8f408279ef1558344a02596fb678a373641b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "950ea8c9536723c82d9a5a2bb3d8f408279ef1558344a02596fb678a373641b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "950ea8c9536723c82d9a5a2bb3d8f408279ef1558344a02596fb678a373641b2", kill_on_drop: false }`
[INFO] [stdout] 950ea8c9536723c82d9a5a2bb3d8f408279ef1558344a02596fb678a373641b2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 60aff0378ca122fbe7fc723cea37d1c4e40bef5c0e461acc44c08503c98db6f1
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "60aff0378ca122fbe7fc723cea37d1c4e40bef5c0e461acc44c08503c98db6f1", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling syn v1.0.68
[INFO] [stderr]     Checking byteorder v1.4.3
[INFO] [stderr]     Checking plotters-backend v0.3.0
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]     Checking oorandom v11.1.3
[INFO] [stderr]     Checking minigrep v0.1.0 (/opt/rustwide/workdir/minigrep)
[INFO] [stderr]     Checking closures v0.1.0 (/opt/rustwide/workdir/closures)
[INFO] [stderr]     Checking iterators v0.1.0 (/opt/rustwide/workdir/iterators)
[INFO] [stderr]     Checking traits v0.1.0 (/opt/rustwide/workdir/traits)
[INFO] [stderr]     Checking errors v0.1.0 (/opt/rustwide/workdir/errors)
[INFO] [stderr]     Checking lifetimes v0.1.0 (/opt/rustwide/workdir/lifetimes)
[INFO] [stderr]     Checking functions v0.1.0 (/opt/rustwide/workdir/functions)
[INFO] [stderr]     Checking smart_pointers v0.1.0 (/opt/rustwide/workdir/smart_pointers)
[INFO] [stdout] warning: unused variable: `tweet`
[INFO] [stdout]   --> traits/src/main.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let tweet = Tweet {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_tweet`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return value referencing temporary value
[INFO] [stdout]  --> traits/src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |         &self.summarize()[0..4]
[INFO] [stdout]   |         ^----------------^^^^^^
[INFO] [stdout]   |         ||
[INFO] [stdout]   |         |temporary value created here
[INFO] [stdout]   |         returns a value referencing data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> errors/src/main.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let f = read_file("Hello.txt".to_string());
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0515`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `traits`
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]   --> closures/src/main.rs:82:9
[INFO] [stdout]    |
[INFO] [stdout] 82 |     let v1 = c.value(1);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simulated_expensive_calculation`
[INFO] [stdout]   --> closures/src/main.rs:72:4
[INFO] [stdout]    |
[INFO] [stdout] 72 | fn simulated_expensive_calculation(intensity: u32) -> u32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tweet`
[INFO] [stdout]   --> traits/src/main.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let tweet = Tweet {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_tweet`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0515]: cannot return value referencing temporary value
[INFO] [stdout]  --> traits/src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |         &self.summarize()[0..4]
[INFO] [stdout]   |         ^----------------^^^^^^
[INFO] [stdout]   |         ||
[INFO] [stdout]   |         |temporary value created here
[INFO] [stdout]   |         returns a value referencing data owned by the current function
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0515`.
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `ImportantExcerpt`
[INFO] [stdout]   --> lifetimes/src/main.rs:22:8
[INFO] [stdout]    |
[INFO] [stdout] 22 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `longest_with_an_announcement`
[INFO] [stdout]   --> lifetimes/src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |     fn longest_with_an_announcement<T>(x: &'a str, y: &'a str, ann: T) -> &'a str
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type `Rc_List` should have an upper camel case name
[INFO] [stdout]   --> smart_pointers/src/main.rs:68:6
[INFO] [stdout]    |
[INFO] [stdout] 68 | enum Rc_List {
[INFO] [stdout]    |      ^^^^^^^ help: convert the identifier to upper camel case: `RcList`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Rc_Cons` should have an upper camel case name
[INFO] [stdout]   --> smart_pointers/src/main.rs:69:5
[INFO] [stdout]    |
[INFO] [stdout] 69 |     Rc_Cons(RefCell<i32>, Rc<Rc_List>),
[INFO] [stdout]    |     ^^^^^^^ help: convert the identifier to upper camel case: `RcCons`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Rc_Nil` should have an upper camel case name
[INFO] [stdout]   --> smart_pointers/src/main.rs:70:5
[INFO] [stdout]    |
[INFO] [stdout] 70 |     Rc_Nil,
[INFO] [stdout]    |     ^^^^^^ help: convert the identifier to upper camel case: `RcNil`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]   --> smart_pointers/src/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let list = Cons(1, Box::new(Cons(2, Box::new(Cons(3, Box::new(Nil))))));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> smart_pointers/src/main.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let x = 5;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> smart_pointers/src/main.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let b = Cons(3, Box::new(a));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b_rc`
[INFO] [stdout]   --> smart_pointers/src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let b_rc = Rc_Cons(RefCell::new(3), Rc::clone(&a_rc));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_b_rc`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c_rc`
[INFO] [stdout]   --> smart_pointers/src/main.rs:41:13
[INFO] [stdout]    |
[INFO] [stdout] 41 |         let c_rc = Rc_Cons(RefCell::new(4), Rc::clone(&a_rc));
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_c_rc`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]   --> smart_pointers/src/main.rs:55:24
[INFO] [stdout]    |
[INFO] [stdout] 55 |         Rc_Cons(value, list) => *value.borrow_mut() += 10,
[INFO] [stdout]    |                        ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `iter_mut` found for struct `Counter` in the current scope
[INFO] [stdout]   --> iterators/src/main.rs:27:32
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let counter_iter = counter.iter_mut();
[INFO] [stdout]    |                                ^^^^^^^^ method not found in `Counter`
[INFO] [stdout] ...
[INFO] [stdout] 30 | struct Counter {
[INFO] [stdout]    | -------------- method `iter_mut` not found for this
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "60aff0378ca122fbe7fc723cea37d1c4e40bef5c0e461acc44c08503c98db6f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60aff0378ca122fbe7fc723cea37d1c4e40bef5c0e461acc44c08503c98db6f1", kill_on_drop: false }`
[INFO] [stdout] 60aff0378ca122fbe7fc723cea37d1c4e40bef5c0e461acc44c08503c98db6f1