[INFO] cloning repository https://github.com/prateekjoshi2013/rust-primer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/prateekjoshi2013/rust-primer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprateekjoshi2013%2Frust-primer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprateekjoshi2013%2Frust-primer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e098cbb5e2cf6da3064d9e5935660846087fd549
[INFO] checking prateekjoshi2013/rust-primer against master#1f12b9b0fdbe735968ac002792a720f0ba4faca6 for crater-rollup-uwu
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fprateekjoshi2013%2Frust-primer" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/prateekjoshi2013/rust-primer on toolchain 1f12b9b0fdbe735968ac002792a720f0ba4faca6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/prateekjoshi2013/rust-primer
[INFO] finished tweaking git repo https://github.com/prateekjoshi2013/rust-primer
[INFO] tweaked toml for git repo https://github.com/prateekjoshi2013/rust-primer written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/prateekjoshi2013/rust-primer 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" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: unused manifest key: part_31_tests
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded cc v1.0.84
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 51607a089aa10244de1740165257a02c7e6a1301d121d30ddc89e8b93f6d4779
[INFO] running `Command { std: "docker" "start" "-a" "51607a089aa10244de1740165257a02c7e6a1301d121d30ddc89e8b93f6d4779", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "51607a089aa10244de1740165257a02c7e6a1301d121d30ddc89e8b93f6d4779", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51607a089aa10244de1740165257a02c7e6a1301d121d30ddc89e8b93f6d4779", kill_on_drop: false }`
[INFO] [stdout] 51607a089aa10244de1740165257a02c7e6a1301d121d30ddc89e8b93f6d4779
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+1f12b9b0fdbe735968ac002792a720f0ba4faca6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8eeffd212abd36032503f653be881a8c79a1613f212b6449e553aef6e22f83a2
[INFO] running `Command { std: "docker" "start" "-a" "8eeffd212abd36032503f653be881a8c79a1613f212b6449e553aef6e22f83a2", kill_on_drop: false }`
[INFO] [stderr] warning: unused manifest key: part_31_tests
[INFO] [stderr]    Compiling libc v0.2.150
[INFO] [stderr]    Compiling proc-macro2 v1.0.69
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling parking_lot_core v0.9.9
[INFO] [stderr]     Checking smallvec v1.11.2
[INFO] [stderr]     Checking memchr v2.6.4
[INFO] [stderr]     Checking regex-syntax v0.8.2
[INFO] [stderr]     Checking bytes v1.5.0
[INFO] [stderr]     Checking pin-project-lite v0.2.13
[INFO] [stderr]    Compiling lock_api v0.4.11
[INFO] [stderr]     Checking aho-corasick v1.1.2
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]     Checking num_cpus v1.16.0
[INFO] [stderr]     Checking socket2 v0.5.5
[INFO] [stderr]     Checking mio v0.8.9
[INFO] [stderr]     Checking signal-hook-registry v1.4.1
[INFO] [stderr]    Compiling syn v2.0.39
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]     Checking regex-automata v0.4.3
[INFO] [stderr]    Compiling tokio-macros v2.2.0
[INFO] [stderr]     Checking regex v1.10.2
[INFO] [stderr]     Checking tokio v1.34.0
[INFO] [stderr]     Checking learning_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_12_part_2_async_await_tasks.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for i in 0..100_000_000 {}
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_12_part_2_async_await_tasks.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     for i in 0..100_000_000 {}
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec2`
[INFO] [stdout]  --> src/projects/part_5_problem_solving/part_5_longest_consecutive_chain.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let vec2=vec![3, 1, 15, 5, 13, 12, 10, 14, 15, 16, 17, 18, 8, 9];
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec3`
[INFO] [stdout]  --> src/projects/part_5_problem_solving/part_5_longest_consecutive_chain.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let vec3=vec![4, 1, 3, 2, 5, 6, 8, 10, 11];
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec2`
[INFO] [stdout]  --> src/projects/part_5_problem_solving/part_5_longest_consecutive_chain.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let vec2=vec![3, 1, 15, 5, 13, 12, 10, 14, 15, 16, 17, 18, 8, 9];
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec3`
[INFO] [stdout]  --> src/projects/part_5_problem_solving/part_5_longest_consecutive_chain.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let vec3=vec![4, 1, 3, 2, 5, 6, 8, 10, 11];
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/tutorial/part_15_option_enum.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 21 |     if let val = some_value {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `disease` is never read
[INFO] [stdout]  --> src/tutorial/part_15_option_enum.rs:8:13
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut disease = None;
[INFO] [stdout]   |             ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]  --> src/tutorial/part_18_lifetimes.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let i: &i32;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]  --> src/tutorial/part_18_lifetimes.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |         let j = 5;
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `last_name`
[INFO] [stdout]   --> src/tutorial/part_18_lifetimes.rs:95:13
[INFO] [stdout]    |
[INFO] [stdout] 95 |         let last_name = String::from("Azam");
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_last_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_18_lifetimes.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     let mut person = Person {
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_19_closures.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let mut vec1 = vec![1, 2, 3];
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/tutorial/part_15_option_enum.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 21 |     if let val = some_value {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stack_ref`
[INFO] [stdout]   --> src/tutorial/part_22_box_smart_pointer.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let stack_ref = &stack_var;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_stack_ref`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `disease` is never read
[INFO] [stdout]  --> src/tutorial/part_15_option_enum.rs:8:13
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut disease = None;
[INFO] [stdout]   |             ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: maybe it is overwritten before being read?
[INFO] [stdout]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/tutorial/part_24_refcell_smart_pointers.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let b = a.borrow_mut();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]  --> src/tutorial/part_18_lifetimes.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let i: &i32;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `j`
[INFO] [stdout]  --> src/tutorial/part_18_lifetimes.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |         let j = 5;
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_j`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `last_name`
[INFO] [stdout]   --> src/tutorial/part_18_lifetimes.rs:95:13
[INFO] [stdout]    |
[INFO] [stdout] 95 |         let last_name = String::from("Azam");
[INFO] [stdout]    |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_last_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_18_lifetimes.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     let mut person = Person {
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]    --> src/tutorial/part_26_declarative_macros.rs:61:9
[INFO] [stdout]     |
[INFO] [stdout] 61  |         $var = $var + 1;
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 112 |     some_macro!(x);
[INFO] [stdout]     |     -------------- in this macro invocation
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: this warning originates in the macro `some_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_19_closures.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let mut vec1 = vec![1, 2, 3];
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tutorial/part_26_declarative_macros.rs:88:17
[INFO] [stdout]     |
[INFO] [stdout] 88  |             let mut res=String::new();
[INFO] [stdout]     |                 ----^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 123 |     let str_null = repeating_concat!();
[INFO] [stdout]     |                    ------------------- in this macro invocation
[INFO] [stdout]     |
[INFO] [stdout]     = note: this warning originates in the macro `repeating_concat` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let m = returns_nothing();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let m = {};
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let m = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let a = m.a;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stack_ref`
[INFO] [stdout]   --> src/tutorial/part_22_box_smart_pointer.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let stack_ref = &stack_var;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_stack_ref`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `finalized_config`
[INFO] [stdout]   --> src/tutorial/part_34_disabling_mutability_for_finalized_obj.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut finalized_config = my_config.build();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_finalized_config`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_34_disabling_mutability_for_finalized_obj.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut finalized_config = my_config.build();
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/tutorial/part_24_refcell_smart_pointers.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let b = a.borrow_mut();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]    --> src/tutorial/part_26_declarative_macros.rs:61:9
[INFO] [stdout]     |
[INFO] [stdout] 61  |         $var = $var + 1;
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 112 |     some_macro!(x);
[INFO] [stdout]     |     -------------- in this macro invocation
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: this warning originates in the macro `some_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tutorial/part_26_declarative_macros.rs:88:17
[INFO] [stdout]     |
[INFO] [stdout] 88  |             let mut res=String::new();
[INFO] [stdout]     |                 ----^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 123 |     let str_null = repeating_concat!();
[INFO] [stdout]     |                    ------------------- in this macro invocation
[INFO] [stdout]     |
[INFO] [stdout]     = note: this warning originates in the macro `repeating_concat` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let m = returns_nothing();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let m = {};
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let m = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/tutorial/part_27_unit_stmt_expr_partial_move.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let a = m.a;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_12_part_4_async_await_join.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut results =
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `send_result`
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_3_channels.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |         let send_result: () = tx.send(String::from("Sent String")).unwrap_or(());
[INFO] [stdout]   |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_send_result`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_4_recieve_as_iterator.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let t = thread::spawn(move || {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_4_recieve_as_iterator.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let t = thread::spawn(move || {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `finalized_config`
[INFO] [stdout]   --> src/tutorial/part_34_disabling_mutability_for_finalized_obj.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut finalized_config = my_config.build();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_finalized_config`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_34_disabling_mutability_for_finalized_obj.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut finalized_config = my_config.build();
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num1`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut num1=m.lock().unwrap();
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_num1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num2`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:18:13
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut num2=m.lock().unwrap(); 
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_num2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut num1=m.lock().unwrap();
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut num2=m.lock().unwrap(); 
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_8_passing_mutexes_between_threads.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let mut mutex = Arc::new(Mutex::new(0));
[INFO] [stdout]   |         ----^^^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file`
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_1_basic_file_manipulation.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut file = File::create(path)?;
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_file`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_1_basic_file_manipulation.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut file = File::create(path)?;
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `path`
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_2_file_system_manipulation.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let path = [
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_path`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_2_file_system_manipulation.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let mut curr = env::current_dir().expect("Can't access current directory");
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_12_part_4_async_await_join.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut results =
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `send_result`
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_3_channels.rs:6:13
[INFO] [stdout]   |
[INFO] [stdout] 6 |         let send_result: () = tx.send(String::from("Sent String")).unwrap_or(());
[INFO] [stdout]   |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_send_result`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_4_recieve_as_iterator.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let t = thread::spawn(move || {
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_4_recieve_as_iterator.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let t = thread::spawn(move || {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_41_web_server/part_41_1_multithreaded_server.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let mut active_requests = Arc::new(Mutex::new(0));
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num1`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut num1=m.lock().unwrap();
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_num1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num2`
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:18:13
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut num2=m.lock().unwrap(); 
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_num2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut num1=m.lock().unwrap();
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_7_sharing_state.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut num2=m.lock().unwrap(); 
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/tutorial/part_38_concurrency/part_8_passing_mutexes_between_threads.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let mut mutex = Arc::new(Mutex::new(0));
[INFO] [stdout]   |         ----^^^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value passed to `var` is never read
[INFO] [stdout]    --> src/tutorial/part_6_ownership.rs:119:23
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn stack_function(mut var: i32) {
[INFO] [stdout]     |                       ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file`
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_1_basic_file_manipulation.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut file = File::create(path)?;
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_file`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_1_basic_file_manipulation.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut file = File::create(path)?;
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `path`
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_2_file_system_manipulation.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let path = [
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_path`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_39_file_handling/part_2_file_system_manipulation.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let mut curr = env::current_dir().expect("Can't access current directory");
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tutorial/part_41_web_server/part_41_1_multithreaded_server.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let mut active_requests = Arc::new(Mutex::new(0));
[INFO] [stdout]    |         ----^^^^^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_1_thread_basics.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     t.join(); // makes the main thread wait untill the spawned thread complete
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let _ = t.join(); // makes the main thread wait untill the spawned thread complete
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_2_multiple_threads_and_ownership.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         join_handle.join();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let _ = join_handle.join();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_3_channels.rs:58:5
[INFO] [stdout]    |
[INFO] [stdout] 58 |     _t_handle.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let _ = _t_handle.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_5_mutiple_sender_threads.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 45 |     join_handle_thread_2.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let _ = join_handle_thread_2.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_5_mutiple_sender_threads.rs:46:5
[INFO] [stdout]    |
[INFO] [stdout] 46 |     join_handle_thread_1.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let _ = join_handle_thread_1.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value passed to `var` is never read
[INFO] [stdout]    --> src/tutorial/part_6_ownership.rs:119:23
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn stack_function(mut var: i32) {
[INFO] [stdout]     |                       ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 40 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_1_thread_basics.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     t.join(); // makes the main thread wait untill the spawned thread complete
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let _ = t.join(); // makes the main thread wait untill the spawned thread complete
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_2_multiple_threads_and_ownership.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         join_handle.join();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let _ = join_handle.join();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_3_channels.rs:58:5
[INFO] [stdout]    |
[INFO] [stdout] 58 |     _t_handle.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let _ = _t_handle.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_5_mutiple_sender_threads.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 45 |     join_handle_thread_2.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let _ = join_handle_thread_2.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/tutorial/part_38_concurrency/part_5_mutiple_sender_threads.rs:46:5
[INFO] [stdout]    |
[INFO] [stdout] 46 |     join_handle_thread_1.join();
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let _ = join_handle_thread_1.join();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 40 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.41s
[INFO] running `Command { std: "docker" "inspect" "8eeffd212abd36032503f653be881a8c79a1613f212b6449e553aef6e22f83a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8eeffd212abd36032503f653be881a8c79a1613f212b6449e553aef6e22f83a2", kill_on_drop: false }`
[INFO] [stdout] 8eeffd212abd36032503f653be881a8c79a1613f212b6449e553aef6e22f83a2