[INFO] cloning repository https://github.com/tperdue321/rust_ownership [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tperdue321/rust_ownership" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftperdue321%2Frust_ownership", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftperdue321%2Frust_ownership'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 66673718162c26f2488175f590ac5890d467a7e6 [INFO] testing tperdue321/rust_ownership against beta-2022-04-10 for beta-1.61-1 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftperdue321%2Frust_ownership" "/workspace/builds/worker-4/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/tperdue321/rust_ownership on toolchain beta-2022-04-10 [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/tperdue321/rust_ownership [INFO] finished tweaking git repo https://github.com/tperdue321/rust_ownership [INFO] tweaked toml for git repo https://github.com/tperdue321/rust_ownership written to /workspace/builds/worker-4/source/Cargo.toml [INFO] crate git repo https://github.com/tperdue321/rust_ownership already has a lockfile, it will not be regenerated [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 6a8fc326b85538129e4aea5da8793a5840dc3bdeb91236be2a4c045fb2633637 [INFO] running `Command { std: "docker" "start" "-a" "6a8fc326b85538129e4aea5da8793a5840dc3bdeb91236be2a4c045fb2633637", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "6a8fc326b85538129e4aea5da8793a5840dc3bdeb91236be2a4c045fb2633637", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6a8fc326b85538129e4aea5da8793a5840dc3bdeb91236be2a4c045fb2633637", kill_on_drop: false }` [INFO] [stdout] 6a8fc326b85538129e4aea5da8793a5840dc3bdeb91236be2a4c045fb2633637 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] ec15ff675d7d6f6d148707b6d21f32c92f1c64951b94d7347f27f02f8e429e68 [INFO] running `Command { std: "docker" "start" "-a" "ec15ff675d7d6f6d148707b6d21f32c92f1c64951b94d7347f27f02f8e429e68", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Compiling ownership v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused variable: `string` [INFO] [stdout] --> src/main.rs:13:13 [INFO] [stdout] | [INFO] [stdout] 13 | let string = "hello"; // string is valid from here forward [INFO] [stdout] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_string` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `s2` [INFO] [stdout] --> src/main.rs:40:9 [INFO] [stdout] | [INFO] [stdout] 40 | let s2 = s1; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_s2` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `s1` [INFO] [stdout] --> src/main.rs:68:9 [INFO] [stdout] | [INFO] [stdout] 68 | let s1 = gives_ownership(); // gives_ownership moves its return [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_s1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r1` [INFO] [stdout] --> src/main.rs:98:9 [INFO] [stdout] | [INFO] [stdout] 98 | let r1 = &mut s2; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r3` [INFO] [stdout] --> src/main.rs:107:13 [INFO] [stdout] | [INFO] [stdout] 107 | let r3 = &mut s3; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r3` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r4` [INFO] [stdout] --> src/main.rs:110:9 [INFO] [stdout] | [INFO] [stdout] 110 | let r4 = &mut s3; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r4` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r1` [INFO] [stdout] --> src/main.rs:113:9 [INFO] [stdout] | [INFO] [stdout] 113 | let r1 = &s; // immutable ref [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r2` [INFO] [stdout] --> src/main.rs:114:9 [INFO] [stdout] | [INFO] [stdout] 114 | let r2 = &s; // second because as many refs can read the same data safely [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r2` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:140:9 [INFO] [stdout] | [INFO] [stdout] 140 | let slice = &s[0..2]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:141:9 [INFO] [stdout] | [INFO] [stdout] 141 | let slice = &s[..2]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:145:9 [INFO] [stdout] | [INFO] [stdout] 145 | let slice = &s[2..len]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:146:9 [INFO] [stdout] | [INFO] [stdout] 146 | let slice = &s[2..]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:148:9 [INFO] [stdout] | [INFO] [stdout] 148 | let slice = &s[0..len]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:149:9 [INFO] [stdout] | [INFO] [stdout] 149 | let slice = &s[..]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:166:9 [INFO] [stdout] | [INFO] [stdout] 166 | let slice = &a[0..2]; [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/main.rs:112:9 [INFO] [stdout] | [INFO] [stdout] 112 | let mut s = String::from("hello s"); [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: 16 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 10.12s [INFO] running `Command { std: "docker" "inspect" "ec15ff675d7d6f6d148707b6d21f32c92f1c64951b94d7347f27f02f8e429e68", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "ec15ff675d7d6f6d148707b6d21f32c92f1c64951b94d7347f27f02f8e429e68", kill_on_drop: false }` [INFO] [stdout] ec15ff675d7d6f6d148707b6d21f32c92f1c64951b94d7347f27f02f8e429e68 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] b8becadb8c2eb6df2b853402544a26541cc9579a232639f8368ef3fd0989ae73 [INFO] running `Command { std: "docker" "start" "-a" "b8becadb8c2eb6df2b853402544a26541cc9579a232639f8368ef3fd0989ae73", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Compiling ownership v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused variable: `string` [INFO] [stdout] --> src/main.rs:13:13 [INFO] [stdout] | [INFO] [stdout] 13 | let string = "hello"; // string is valid from here forward [INFO] [stdout] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_string` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `s2` [INFO] [stdout] --> src/main.rs:40:9 [INFO] [stdout] | [INFO] [stdout] 40 | let s2 = s1; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_s2` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `s1` [INFO] [stdout] --> src/main.rs:68:9 [INFO] [stdout] | [INFO] [stdout] 68 | let s1 = gives_ownership(); // gives_ownership moves its return [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_s1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r1` [INFO] [stdout] --> src/main.rs:98:9 [INFO] [stdout] | [INFO] [stdout] 98 | let r1 = &mut s2; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r3` [INFO] [stdout] --> src/main.rs:107:13 [INFO] [stdout] | [INFO] [stdout] 107 | let r3 = &mut s3; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r3` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r4` [INFO] [stdout] --> src/main.rs:110:9 [INFO] [stdout] | [INFO] [stdout] 110 | let r4 = &mut s3; [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r4` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r1` [INFO] [stdout] --> src/main.rs:113:9 [INFO] [stdout] | [INFO] [stdout] 113 | let r1 = &s; // immutable ref [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `r2` [INFO] [stdout] --> src/main.rs:114:9 [INFO] [stdout] | [INFO] [stdout] 114 | let r2 = &s; // second because as many refs can read the same data safely [INFO] [stdout] | ^^ help: if this is intentional, prefix it with an underscore: `_r2` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:140:9 [INFO] [stdout] | [INFO] [stdout] 140 | let slice = &s[0..2]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:141:9 [INFO] [stdout] | [INFO] [stdout] 141 | let slice = &s[..2]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:145:9 [INFO] [stdout] | [INFO] [stdout] 145 | let slice = &s[2..len]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:146:9 [INFO] [stdout] | [INFO] [stdout] 146 | let slice = &s[2..]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:148:9 [INFO] [stdout] | [INFO] [stdout] 148 | let slice = &s[0..len]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:149:9 [INFO] [stdout] | [INFO] [stdout] 149 | let slice = &s[..]; // same [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `slice` [INFO] [stdout] --> src/main.rs:166:9 [INFO] [stdout] | [INFO] [stdout] 166 | let slice = &a[0..2]; [INFO] [stdout] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/main.rs:112:9 [INFO] [stdout] | [INFO] [stdout] 112 | let mut s = String::from("hello s"); [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: 16 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 0.33s [INFO] [stderr] Executable unittests src/main.rs (/opt/rustwide/target/debug/deps/ownership-9897b59f1ce90ebb) [INFO] running `Command { std: "docker" "inspect" "b8becadb8c2eb6df2b853402544a26541cc9579a232639f8368ef3fd0989ae73", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "b8becadb8c2eb6df2b853402544a26541cc9579a232639f8368ef3fd0989ae73", kill_on_drop: false }` [INFO] [stdout] b8becadb8c2eb6df2b853402544a26541cc9579a232639f8368ef3fd0989ae73 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen", kill_on_drop: false }` [INFO] [stdout] 9b208ed9041e58f5751514ef4a6e3d40756f0cbc4fef07b7280ee093c34292d7 [INFO] running `Command { std: "docker" "start" "-a" "9b208ed9041e58f5751514ef4a6e3d40756f0cbc4fef07b7280ee093c34292d7", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] warning: unused variable: `string` [INFO] [stderr] --> src/main.rs:13:13 [INFO] [stderr] | [INFO] [stderr] 13 | let string = "hello"; // string is valid from here forward [INFO] [stderr] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_string` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_variables)]` on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `s2` [INFO] [stderr] --> src/main.rs:40:9 [INFO] [stderr] | [INFO] [stderr] 40 | let s2 = s1; [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_s2` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `s1` [INFO] [stderr] --> src/main.rs:68:9 [INFO] [stderr] | [INFO] [stderr] 68 | 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: `r1` [INFO] [stderr] --> src/main.rs:98:9 [INFO] [stderr] | [INFO] [stderr] 98 | let r1 = &mut s2; [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `r3` [INFO] [stderr] --> src/main.rs:107:13 [INFO] [stderr] | [INFO] [stderr] 107 | let r3 = &mut s3; [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_r3` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `r4` [INFO] [stderr] --> src/main.rs:110:9 [INFO] [stderr] | [INFO] [stderr] 110 | let r4 = &mut s3; [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_r4` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `r1` [INFO] [stderr] --> src/main.rs:113:9 [INFO] [stderr] | [INFO] [stderr] 113 | let r1 = &s; // immutable ref [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_r1` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `r2` [INFO] [stderr] --> src/main.rs:114:9 [INFO] [stderr] | [INFO] [stderr] 114 | let r2 = &s; // second because as many refs can read the same data safely [INFO] [stderr] | ^^ help: if this is intentional, prefix it with an underscore: `_r2` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:140:9 [INFO] [stderr] | [INFO] [stderr] 140 | let slice = &s[0..2]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:141:9 [INFO] [stderr] | [INFO] [stderr] 141 | let slice = &s[..2]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:145:9 [INFO] [stderr] | [INFO] [stderr] 145 | let slice = &s[2..len]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:146:9 [INFO] [stderr] | [INFO] [stderr] 146 | let slice = &s[2..]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:148:9 [INFO] [stderr] | [INFO] [stderr] 148 | let slice = &s[0..len]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:149:9 [INFO] [stderr] | [INFO] [stderr] 149 | let slice = &s[..]; // same [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `slice` [INFO] [stderr] --> src/main.rs:166:9 [INFO] [stderr] | [INFO] [stderr] 166 | let slice = &a[0..2]; [INFO] [stderr] | ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice` [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/main.rs:112:9 [INFO] [stderr] | [INFO] [stderr] 112 | let mut s = String::from("hello s"); [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: `ownership` (bin "ownership" test) generated 16 warnings [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 0.15s [INFO] [stderr] Running unittests src/main.rs (/opt/rustwide/target/debug/deps/ownership-9897b59f1ce90ebb) [INFO] [stdout] [INFO] [stdout] running 0 tests [INFO] [stdout] [INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s [INFO] [stdout] [INFO] running `Command { std: "docker" "inspect" "9b208ed9041e58f5751514ef4a6e3d40756f0cbc4fef07b7280ee093c34292d7", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "9b208ed9041e58f5751514ef4a6e3d40756f0cbc4fef07b7280ee093c34292d7", kill_on_drop: false }` [INFO] [stdout] 9b208ed9041e58f5751514ef4a6e3d40756f0cbc4fef07b7280ee093c34292d7