[INFO] updating cached 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" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dbbcf257a78bae12cff841f781eac3a6ae9ccac3
[INFO] checking kbacha/string-clone-performance-rust against master#c724b67e1b474262917a5154d74e7072267593fe for pr-74315
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkbacha%2Fstring-clone-performance-rust" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kbacha/string-clone-performance-rust on toolchain c724b67e1b474262917a5154d74e7072267593fe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "read-manifest" "--manifest-path" "Cargo.toml", 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-11/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" "+c724b67e1b474262917a5154d74e7072267593fe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 205e2f426b1a81e778245a0ccf33832564dbdadfa02ba6826661a2a87f9b51f9
[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" "205e2f426b1a81e778245a0ccf33832564dbdadfa02ba6826661a2a87f9b51f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "205e2f426b1a81e778245a0ccf33832564dbdadfa02ba6826661a2a87f9b51f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "205e2f426b1a81e778245a0ccf33832564dbdadfa02ba6826661a2a87f9b51f9", kill_on_drop: false }`
[INFO] [stdout] 205e2f426b1a81e778245a0ccf33832564dbdadfa02ba6826661a2a87f9b51f9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dbf7532e7a11aa876486f861e76567c5966fc864803d307e9eb300be9a20f3d4
[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" "dbf7532e7a11aa876486f861e76567c5966fc864803d307e9eb300be9a20f3d4", kill_on_drop: false }`
[INFO] [stderr]     Checking string-clone-performance v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 `std::clone::Clone::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 0.58s
[INFO] running `Command { std: "docker" "inspect" "dbf7532e7a11aa876486f861e76567c5966fc864803d307e9eb300be9a20f3d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbf7532e7a11aa876486f861e76567c5966fc864803d307e9eb300be9a20f3d4", kill_on_drop: false }`
[INFO] [stdout] dbf7532e7a11aa876486f861e76567c5966fc864803d307e9eb300be9a20f3d4