[INFO] fetching crate wtf8-rs 1.0.0...
[INFO] checking wtf8-rs-1.0.0 against try#8de4b308b608cded0ebccf658a0fc719bce87d4e for pr-89056
[INFO] extracting crate wtf8-rs 1.0.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate wtf8-rs 1.0.0 on toolchain 8de4b308b608cded0ebccf658a0fc719bce87d4e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate wtf8-rs 1.0.0
[INFO] finished tweaking crates.io crate wtf8-rs 1.0.0
[INFO] tweaked toml for crates.io crate wtf8-rs 1.0.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 98d636641367f0bb62eba601105450f16c7b89ae4160d857e9ce5e8921522f2a
[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" "98d636641367f0bb62eba601105450f16c7b89ae4160d857e9ce5e8921522f2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "98d636641367f0bb62eba601105450f16c7b89ae4160d857e9ce5e8921522f2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "98d636641367f0bb62eba601105450f16c7b89ae4160d857e9ce5e8921522f2a", kill_on_drop: false }`
[INFO] [stdout] 98d636641367f0bb62eba601105450f16c7b89ae4160d857e9ce5e8921522f2a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 18f2b0c035b0df7171792208bf6b0096119d54f4906ce244984c0e72a2d67213
[INFO] running `Command { std: "docker" "start" "-a" "18f2b0c035b0df7171792208bf6b0096119d54f4906ce244984c0e72a2d67213", kill_on_drop: false }`
[INFO] [stderr]     Checking wtf8-rs v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/wtf8/tests.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 29 |     &Wtf8::new("aé 💩")[2..4];
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let _ = &Wtf8::new("aé 💩")[2..4];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/wtf8/tests.rs:40:5
[INFO] [stdout]    |
[INFO] [stdout] 40 |     &Wtf8::new("aé 💩")[2..];
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let _ = &Wtf8::new("aé 💩")[2..];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/wtf8/tests.rs:51:5
[INFO] [stdout]    |
[INFO] [stdout] 51 |     &Wtf8::new("aé 💩")[5..];
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let _ = &Wtf8::new("aé 💩")[5..];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.96s
[INFO] running `Command { std: "docker" "inspect" "18f2b0c035b0df7171792208bf6b0096119d54f4906ce244984c0e72a2d67213", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "18f2b0c035b0df7171792208bf6b0096119d54f4906ce244984c0e72a2d67213", kill_on_drop: false }`
[INFO] [stdout] 18f2b0c035b0df7171792208bf6b0096119d54f4906ce244984c0e72a2d67213