[INFO] updating cached repository https://github.com/fnick851/rust-the-book
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 89593b4179cbb581f9f7fe49ad516af2d35f0ab7
[INFO] checking fnick851/rust-the-book against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffnick851%2Frust-the-book" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fnick851/rust-the-book on toolchain e4dba30b9b475d8750370c4dfb49b6541990904d
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/fnick851/rust-the-book
[INFO] finished tweaking git repo https://github.com/fnick851/rust-the-book
[INFO] tweaked toml for git repo https://github.com/fnick851/rust-the-book written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/fnick851/rust-the-book already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 09b025347232b8304effb5119b306f57ba9db568e9dad513f2d6b258d0267f5a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "09b025347232b8304effb5119b306f57ba9db568e9dad513f2d6b258d0267f5a"`
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking backtrace v0.3.40
[INFO] [stderr]     Checking error-chain v0.10.0
[INFO] [stderr]     Checking ferris-says v0.1.1
[INFO] [stderr]     Checking hello_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: field is never read: `seasonal_fruit`
[INFO] [stderr]   --> src/bin/super_path.rs:14:9
[INFO] [stderr]    |
[INFO] [stderr] 14 |         seasonal_fruit: String,
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]  --> src/bin/ownership.rs:5:13
[INFO] [stderr]   |
[INFO] [stderr] 5 |         let s = "hello"; // s is valid from this point forward
[INFO] [stderr]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s1`
[INFO] [stderr]   --> src/bin/ownership.rs:50:17
[INFO] [stderr]    |
[INFO] [stderr] 50 |             let s1 = gives_ownership(); // gives_ownership moves its return
[INFO] [stderr]    |                 ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s3`
[INFO] [stderr]   --> src/bin/ownership.rs:55:17
[INFO] [stderr]    |
[INFO] [stderr] 55 |             let s3 = takes_and_gives_back(s2); // s2 is moved into
[INFO] [stderr]    |                 ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]  --> src/bin/ownership.rs:5:13
[INFO] [stderr]   |
[INFO] [stderr] 5 |         let s = "hello"; // s is valid from this point forward
[INFO] [stderr]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s1`
[INFO] [stderr]   --> src/bin/ownership.rs:50:17
[INFO] [stderr]    |
[INFO] [stderr] 50 |             let s1 = gives_ownership(); // gives_ownership moves its return
[INFO] [stderr]    |                 ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s3`
[INFO] [stderr]   --> src/bin/ownership.rs:55:17
[INFO] [stderr]    |
[INFO] [stderr] 55 |             let s3 = takes_and_gives_back(s2); // s2 is moved into
[INFO] [stderr]    |                 ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `state`
[INFO] [stderr]   --> src/bin/enum.rs:29:26
[INFO] [stderr]    |
[INFO] [stderr] 29 |     if let Coin::Quarter(state) = some_value {
[INFO] [stderr]    |                          ^^^^^ help: if this is intentional, prefix it with an underscore: `_state`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 3 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 3 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `seat_at_table`
[INFO] [stderr]  --> src/bin/restrt_lib.rs:6:12
[INFO] [stderr]   |
[INFO] [stderr] 6 |         fn seat_at_table() {}
[INFO] [stderr]   |            ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `take_order`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:10:12
[INFO] [stderr]    |
[INFO] [stderr] 10 |         fn take_order() {}
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `serve_order`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:12:12
[INFO] [stderr]    |
[INFO] [stderr] 12 |         fn serve_order() {}
[INFO] [stderr]    |            ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `take_payment`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:14:12
[INFO] [stderr]    |
[INFO] [stderr] 14 |         fn take_payment() {}
[INFO] [stderr]    |            ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `seat_at_table`
[INFO] [stderr]  --> src/bin/restrt_lib.rs:6:12
[INFO] [stderr]   |
[INFO] [stderr] 6 |         fn seat_at_table() {}
[INFO] [stderr]   |            ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `take_order`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:10:12
[INFO] [stderr]    |
[INFO] [stderr] 10 |         fn take_order() {}
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `serve_order`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:12:12
[INFO] [stderr]    |
[INFO] [stderr] 12 |         fn serve_order() {}
[INFO] [stderr]    |            ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `take_payment`
[INFO] [stderr]   --> src/bin/restrt_lib.rs:14:12
[INFO] [stderr]    |
[INFO] [stderr] 14 |         fn take_payment() {}
[INFO] [stderr]    |            ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/bin/result.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |     let f = match f {
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/bin/result.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     read_username_from_file();
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> src/bin/vector.rs:2:9
[INFO] [stderr]   |
[INFO] [stderr] 2 |     let mut v = vec![1, 2, 3, 4, 5];
[INFO] [stderr]   |         ----^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> src/bin/vector.rs:2:9
[INFO] [stderr]   |
[INFO] [stderr] 2 |     let mut v = vec![1, 2, 3, 4, 5];
[INFO] [stderr]   |         ----^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `seasonal_fruit`
[INFO] [stderr]   --> src/bin/super_path.rs:14:9
[INFO] [stderr]    |
[INFO] [stderr] 14 |         seasonal_fruit: String,
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `state`
[INFO] [stderr]   --> src/bin/enum.rs:29:26
[INFO] [stderr]    |
[INFO] [stderr] 29 |     if let Coin::Quarter(state) = some_value {
[INFO] [stderr]    |                          ^^^^^ help: if this is intentional, prefix it with an underscore: `_state`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Alaska`
[INFO] [stderr]  --> src/bin/enum.rs:5:9
[INFO] [stderr]   |
[INFO] [stderr] 5 |         Alaska,
[INFO] [stderr]   |         ^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Penny`
[INFO] [stderr]  --> src/bin/enum.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |         Penny,
[INFO] [stderr]   |         ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Nickel`
[INFO] [stderr]  --> src/bin/enum.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |         Nickel,
[INFO] [stderr]   |         ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `Dime`
[INFO] [stderr]   --> src/bin/enum.rs:10:9
[INFO] [stderr]    |
[INFO] [stderr] 10 |         Dime,
[INFO] [stderr]    |         ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/bin/result.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |     let f = match f {
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/bin/result.rs:20:5
[INFO] [stderr]    |
[INFO] [stderr] 20 |     read_username_from_file();
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 15.53s
[INFO] running `"docker" "inspect" "09b025347232b8304effb5119b306f57ba9db568e9dad513f2d6b258d0267f5a"`
[INFO] running `"docker" "rm" "-f" "09b025347232b8304effb5119b306f57ba9db568e9dad513f2d6b258d0267f5a"`
[INFO] [stdout] 09b025347232b8304effb5119b306f57ba9db568e9dad513f2d6b258d0267f5a