[INFO] fetching crate cain 0.1.2...
[INFO] checking cain-0.1.2 against nightly-2024-02-05 for check-cfg
[INFO] extracting crate cain 0.1.2 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate cain 0.1.2 on toolchain nightly-2024-02-05
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cain 0.1.2
[INFO] finished tweaking crates.io crate cain 0.1.2
[INFO] tweaked toml for crates.io crate cain 0.1.2 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+nightly-2024-02-05" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ff8b5007e958fb03f4b6f04a33d6ccaeab72889f0a4f2144937149fb59872165
[INFO] running `Command { std: "docker" "start" "-a" "ff8b5007e958fb03f4b6f04a33d6ccaeab72889f0a4f2144937149fb59872165", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ff8b5007e958fb03f4b6f04a33d6ccaeab72889f0a4f2144937149fb59872165", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ff8b5007e958fb03f4b6f04a33d6ccaeab72889f0a4f2144937149fb59872165", kill_on_drop: false }`
[INFO] [stdout] ff8b5007e958fb03f4b6f04a33d6ccaeab72889f0a4f2144937149fb59872165
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+nightly-2024-02-05" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a01dcaa9dea68618faefffe45716536046871f2ee2d96a77029d5aeae918dcb4
[INFO] running `Command { std: "docker" "start" "-a" "a01dcaa9dea68618faefffe45716536046871f2ee2d96a77029d5aeae918dcb4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking pretty_assertions v1.4.0
[INFO] [stderr]     Checking quote v1.0.35
[INFO] [stderr]     Checking cain v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:31:30
[INFO] [stdout]    |
[INFO] [stdout] 31 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:49:30
[INFO] [stdout]    |
[INFO] [stdout] 49 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> tests/diverging_branches.rs:26:25
[INFO] [stdout]    |
[INFO] [stdout] 26 |                     let x = match n {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> tests/diverging_branches.rs:52:25
[INFO] [stdout]    |
[INFO] [stdout] 52 |                     let y = match n % 2 {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> tests/diverging_branches.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let x = match n % 3 {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/no_behavior_change.rs:64:22
[INFO] [stdout]    |
[INFO] [stdout] 64 |                 Some(mut v) => { v.pop(); },
[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]   --> tests/no_behavior_change.rs:78:22
[INFO] [stdout]    |
[INFO] [stdout] 78 |                 Some(mut b) => inc(&mut b),
[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]    --> tests/no_behavior_change.rs:109:22
[INFO] [stdout]     |
[INFO] [stdout] 109 |                 Some(mut b) => inc(&mut b),
[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]    --> tests/no_behavior_change.rs:140:26
[INFO] [stdout]     |
[INFO] [stdout] 140 |                 Some(ref mut b) => inc(b),
[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]    --> tests/no_behavior_change.rs:154:37
[INFO] [stdout]     |
[INFO] [stdout] 154 |             let _ = if let Some(ref mut b) = &mut a {
[INFO] [stdout]     |                                     ----^
[INFO] [stdout]     |                                     |
[INFO] [stdout]     |                                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> tests/no_behavior_change.rs:179:16
[INFO] [stdout]     |
[INFO] [stdout] 179 |             if let None = a {
[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: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.53s
[INFO] running `Command { std: "docker" "inspect" "a01dcaa9dea68618faefffe45716536046871f2ee2d96a77029d5aeae918dcb4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a01dcaa9dea68618faefffe45716536046871f2ee2d96a77029d5aeae918dcb4", kill_on_drop: false }`
[INFO] [stdout] a01dcaa9dea68618faefffe45716536046871f2ee2d96a77029d5aeae918dcb4
[INFO] checking cain-0.1.2 against nightly-2024-02-05+rustflags=-Dunexpected_cfgs+cargoflags=-Zcheck-cfg for check-cfg
[INFO] extracting crate cain 0.1.2 into /workspace/builds/worker-0-tc2/source
[INFO] validating manifest of crates.io crate cain 0.1.2 on toolchain nightly-2024-02-05
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cain 0.1.2
[INFO] finished tweaking crates.io crate cain 0.1.2
[INFO] tweaked toml for crates.io crate cain 0.1.2 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly-2024-02-05" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+nightly-2024-02-05" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d838d04611ef470f54c317be0e568edd13e0517bd09ffd3a66fed524df767c6b
[INFO] running `Command { std: "docker" "start" "-a" "d838d04611ef470f54c317be0e568edd13e0517bd09ffd3a66fed524df767c6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d838d04611ef470f54c317be0e568edd13e0517bd09ffd3a66fed524df767c6b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d838d04611ef470f54c317be0e568edd13e0517bd09ffd3a66fed524df767c6b", kill_on_drop: false }`
[INFO] [stdout] d838d04611ef470f54c317be0e568edd13e0517bd09ffd3a66fed524df767c6b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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 -Dunexpected_cfgs" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+nightly-2024-02-05" "check" "--frozen" "--all" "--all-targets" "--message-format=json" "-Zcheck-cfg", kill_on_drop: false }`
[INFO] [stdout] 882974fcf19e48ec1eef4e904651d7df251868cf46252122d47bdca329a288d9
[INFO] running `Command { std: "docker" "start" "-a" "882974fcf19e48ec1eef4e904651d7df251868cf46252122d47bdca329a288d9", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking pretty_assertions v1.4.0
[INFO] [stderr]     Checking quote v1.0.35
[INFO] [stderr]     Checking cain v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:31:30
[INFO] [stdout]    |
[INFO] [stdout] 31 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:49:30
[INFO] [stdout]    |
[INFO] [stdout] 49 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> tests/diverging_branches.rs:56:30
[INFO] [stdout]    |
[INFO] [stdout] 56 |                         _ => panic!() as &str,
[INFO] [stdout]    |                              --------^^^^^^^^
[INFO] [stdout]    |                              |
[INFO] [stdout]    |                              unreachable expression
[INFO] [stdout]    |                              any code following this expression is unreachable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> tests/diverging_branches.rs:26:25
[INFO] [stdout]    |
[INFO] [stdout] 26 |                     let x = match n {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> tests/diverging_branches.rs:52:25
[INFO] [stdout]    |
[INFO] [stdout] 52 |                     let y = match n % 2 {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> tests/diverging_branches.rs:44:25
[INFO] [stdout]    |
[INFO] [stdout] 44 |                     let x = match n % 3 {
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/no_behavior_change.rs:64:22
[INFO] [stdout]    |
[INFO] [stdout] 64 |                 Some(mut v) => { v.pop(); },
[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]   --> tests/no_behavior_change.rs:78:22
[INFO] [stdout]    |
[INFO] [stdout] 78 |                 Some(mut b) => inc(&mut b),
[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]    --> tests/no_behavior_change.rs:109:22
[INFO] [stdout]     |
[INFO] [stdout] 109 |                 Some(mut b) => inc(&mut b),
[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]    --> tests/no_behavior_change.rs:140:26
[INFO] [stdout]     |
[INFO] [stdout] 140 |                 Some(ref mut b) => inc(b),
[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]    --> tests/no_behavior_change.rs:154:37
[INFO] [stdout]     |
[INFO] [stdout] 154 |             let _ = if let Some(ref mut b) = &mut a {
[INFO] [stdout]     |                                     ----^
[INFO] [stdout]     |                                     |
[INFO] [stdout]     |                                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> tests/no_behavior_change.rs:179:16
[INFO] [stdout]     |
[INFO] [stdout] 179 |             if let None = a {
[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: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.41s
[INFO] running `Command { std: "docker" "inspect" "882974fcf19e48ec1eef4e904651d7df251868cf46252122d47bdca329a288d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "882974fcf19e48ec1eef4e904651d7df251868cf46252122d47bdca329a288d9", kill_on_drop: false }`
[INFO] [stdout] 882974fcf19e48ec1eef4e904651d7df251868cf46252122d47bdca329a288d9
