[INFO] cloning repository https://github.com/kbacha/string-clone-performance-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kbacha/string-clone-performance-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkbacha%2Fstring-clone-performance-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkbacha%2Fstring-clone-performance-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dbbcf257a78bae12cff841f781eac3a6ae9ccac3
[INFO] checking kbacha/string-clone-performance-rust against try#8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8 for pr-82565
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkbacha%2Fstring-clone-performance-rust" "/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/kbacha/string-clone-performance-rust on toolchain 8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kbacha/string-clone-performance-rust
[INFO] finished tweaking git repo https://github.com/kbacha/string-clone-performance-rust
[INFO] tweaked toml for git repo https://github.com/kbacha/string-clone-performance-rust written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/kbacha/string-clone-performance-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "fetch" "--locked" "--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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2f8927d45e897a6c0fcdeb9871650a0f3a9d0361e0356ebc8e37eed31af2e6ed
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "2f8927d45e897a6c0fcdeb9871650a0f3a9d0361e0356ebc8e37eed31af2e6ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f8927d45e897a6c0fcdeb9871650a0f3a9d0361e0356ebc8e37eed31af2e6ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f8927d45e897a6c0fcdeb9871650a0f3a9d0361e0356ebc8e37eed31af2e6ed", kill_on_drop: false }`
[INFO] [stdout] 2f8927d45e897a6c0fcdeb9871650a0f3a9d0361e0356ebc8e37eed31af2e6ed
[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=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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+8e3afc79c11f48cb3acd1be5b3b7de98fe3f93a8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 91e469c4f6cf5682218e72aabbc24ff84e024ec34a3dbc3dd6255655cdcc5db7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "91e469c4f6cf5682218e72aabbc24ff84e024ec34a3dbc3dd6255655cdcc5db7", kill_on_drop: false }`
[INFO] [stderr]     Checking string-clone-performance v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:13:38
[INFO] [stdout]    |
[INFO] [stdout] 13 |     time("100 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                      ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:15:39
[INFO] [stdout]    |
[INFO] [stdout] 15 |     time("1000 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                       ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:17:41
[INFO] [stdout]    |
[INFO] [stdout] 17 |     time("10,000 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:19:41
[INFO] [stdout]    |
[INFO] [stdout] 19 |     time("100,000 rs", 10_000_000, || { s.clone(); });
[INFO] [stdout]    |                                         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:13:38
[INFO] [stdout]    |
[INFO] [stdout] 13 |     time("100 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                      ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:15:39
[INFO] [stdout]    |
[INFO] [stdout] 15 |     time("1000 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                       ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:17:41
[INFO] [stdout]    |
[INFO] [stdout] 17 |     time("10,000 rs", 100_000_000, || { s.clone(); });
[INFO] [stdout]    |                                         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `clone` that must be used
[INFO] [stdout]   --> src/main.rs:19:41
[INFO] [stdout]    |
[INFO] [stdout] 19 |     time("100,000 rs", 10_000_000, || { s.clone(); });
[INFO] [stdout]    |                                         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.80s
[INFO] running `Command { std: "docker" "inspect" "91e469c4f6cf5682218e72aabbc24ff84e024ec34a3dbc3dd6255655cdcc5db7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "91e469c4f6cf5682218e72aabbc24ff84e024ec34a3dbc3dd6255655cdcc5db7", kill_on_drop: false }`
[INFO] [stdout] 91e469c4f6cf5682218e72aabbc24ff84e024ec34a3dbc3dd6255655cdcc5db7