[INFO] updating cached repository https://github.com/kbacha/string-clone-performance-rust
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] dbbcf257a78bae12cff841f781eac3a6ae9ccac3
[INFO] checking kbacha/string-clone-performance-rust against try#e922e6444795ab795fab1943288aee3d543699b8 for pr-66852
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkbacha%2Fstring-clone-performance-rust" "/workspace/builds/worker-4/source"`
[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 e922e6444795ab795fab1943288aee3d543699b8
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e922e6444795ab795fab1943288aee3d543699b8" "read-manifest" "--manifest-path" "Cargo.toml"`
[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 `"/workspace/cargo-home/bin/cargo" "+e922e6444795ab795fab1943288aee3d543699b8" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "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" "/opt/rustwide/cargo-home/bin/cargo" "+e922e6444795ab795fab1943288aee3d543699b8" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7edfc2d3472ade201fd028f6c325bc68ff6788e97fada4aca3703530974b0057
[INFO] running `"docker" "start" "-a" "7edfc2d3472ade201fd028f6c325bc68ff6788e97fada4aca3703530974b0057"`
[INFO] [stderr]     Checking string-clone-performance v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:13:38
[INFO] [stderr]    |
[INFO] [stderr] 13 |     time("100 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                      ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:15:39
[INFO] [stderr]    |
[INFO] [stderr] 15 |     time("1000 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                       ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:17:41
[INFO] [stderr]    |
[INFO] [stderr] 17 |     time("10,000 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                         ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:19:41
[INFO] [stderr]    |
[INFO] [stderr] 19 |     time("100,000 rs", 10_000_000, || { s.clone(); });
[INFO] [stderr]    |                                         ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:13:38
[INFO] [stderr]    |
[INFO] [stderr] 13 |     time("100 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                      ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:15:39
[INFO] [stderr]    |
[INFO] [stderr] 15 |     time("1000 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                       ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:17:41
[INFO] [stderr]    |
[INFO] [stderr] 17 |     time("10,000 rs", 100_000_000, || { s.clone(); });
[INFO] [stderr]    |                                         ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::clone::Clone::clone` that must be used
[INFO] [stderr]   --> src/main.rs:19:41
[INFO] [stderr]    |
[INFO] [stderr] 19 |     time("100,000 rs", 10_000_000, || { s.clone(); });
[INFO] [stderr]    |                                         ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: cloning is often expensive and is not expected to have side effects
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.68s
[INFO] running `"docker" "inspect" "7edfc2d3472ade201fd028f6c325bc68ff6788e97fada4aca3703530974b0057"`
[INFO] running `"docker" "rm" "-f" "7edfc2d3472ade201fd028f6c325bc68ff6788e97fada4aca3703530974b0057"`
[INFO] [stdout] 7edfc2d3472ade201fd028f6c325bc68ff6788e97fada4aca3703530974b0057