[INFO] fetching crate cain 0.1.2...
[INFO] checking cain-0.1.2 against master#b0696a5160711c068cb1f01b7437db7990d15750 for pr-121848
[INFO] extracting crate cain 0.1.2 into /workspace/builds/worker-1-tc1/source
[INFO] validating manifest of crates.io crate cain 0.1.2 on toolchain b0696a5160711c068cb1f01b7437db7990d15750
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b0696a5160711c068cb1f01b7437db7990d15750" "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-1-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b0696a5160711c068cb1f01b7437db7990d15750" "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" "+b0696a5160711c068cb1f01b7437db7990d15750" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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" "+b0696a5160711c068cb1f01b7437db7990d15750" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d3f957d58bdd96bc89605970000a2b09990f8c82474a1065fc39b5f1017cacdd
[INFO] running `Command { std: "docker" "start" "-a" "d3f957d58bdd96bc89605970000a2b09990f8c82474a1065fc39b5f1017cacdd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3f957d58bdd96bc89605970000a2b09990f8c82474a1065fc39b5f1017cacdd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3f957d58bdd96bc89605970000a2b09990f8c82474a1065fc39b5f1017cacdd", kill_on_drop: false }`
[INFO] [stdout] d3f957d58bdd96bc89605970000a2b09990f8c82474a1065fc39b5f1017cacdd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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" "+b0696a5160711c068cb1f01b7437db7990d15750" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 28c707052dde1032bb3443c7c712b1c3915b00523569b88eed3909e5292a1853
[INFO] running `Command { std: "docker" "start" "-a" "28c707052dde1032bb3443c7c712b1c3915b00523569b88eed3909e5292a1853", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking unicode-ident v1.0.12
[INFO] [stderr]     Checking diff v0.1.13
[INFO] [stderr]     Checking yansi v0.5.1
[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` profile [unoptimized + debuginfo] target(s) in 6.71s
[INFO] running `Command { std: "docker" "inspect" "28c707052dde1032bb3443c7c712b1c3915b00523569b88eed3909e5292a1853", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28c707052dde1032bb3443c7c712b1c3915b00523569b88eed3909e5292a1853", kill_on_drop: false }`
[INFO] [stdout] 28c707052dde1032bb3443c7c712b1c3915b00523569b88eed3909e5292a1853
[INFO] checking cain-0.1.2 against try#bfe97fcae016881ad333f0ff8cea2cadb9cf136c for pr-121848
[INFO] extracting crate cain 0.1.2 into /workspace/builds/worker-1-tc2/source
[INFO] validating manifest of crates.io crate cain 0.1.2 on toolchain bfe97fcae016881ad333f0ff8cea2cadb9cf136c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bfe97fcae016881ad333f0ff8cea2cadb9cf136c" "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-1-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bfe97fcae016881ad333f0ff8cea2cadb9cf136c" "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" "+bfe97fcae016881ad333f0ff8cea2cadb9cf136c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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" "+bfe97fcae016881ad333f0ff8cea2cadb9cf136c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f50e502bf86a69ceeef0bea99e4a31ba7d23bc602e4b54aaa7e0fc6b093422c7
[INFO] running `Command { std: "docker" "start" "-a" "f50e502bf86a69ceeef0bea99e4a31ba7d23bc602e4b54aaa7e0fc6b093422c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f50e502bf86a69ceeef0bea99e4a31ba7d23bc602e4b54aaa7e0fc6b093422c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f50e502bf86a69ceeef0bea99e4a31ba7d23bc602e4b54aaa7e0fc6b093422c7", kill_on_drop: false }`
[INFO] [stdout] f50e502bf86a69ceeef0bea99e4a31ba7d23bc602e4b54aaa7e0fc6b093422c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+bfe97fcae016881ad333f0ff8cea2cadb9cf136c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b25db6df3a2bcfaaf5c819c3f1b705d0a34112a0980c3870342cf064490af206
[INFO] running `Command { std: "docker" "start" "-a" "b25db6df3a2bcfaaf5c819c3f1b705d0a34112a0980c3870342cf064490af206", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking unicode-ident v1.0.12
[INFO] [stderr]     Checking diff v0.1.13
[INFO] [stderr]     Checking yansi v0.5.1
[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` profile [unoptimized + debuginfo] target(s) in 7.20s
[INFO] running `Command { std: "docker" "inspect" "b25db6df3a2bcfaaf5c819c3f1b705d0a34112a0980c3870342cf064490af206", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b25db6df3a2bcfaaf5c819c3f1b705d0a34112a0980c3870342cf064490af206", kill_on_drop: false }`
[INFO] [stdout] b25db6df3a2bcfaaf5c819c3f1b705d0a34112a0980c3870342cf064490af206
