[INFO] fetching crate preftool 0.2.0...
[INFO] checking preftool-0.2.0 against master#0d37dca25a51fb900a402c94c8818ad1c2789e30 for pr-77526
[INFO] extracting crate preftool 0.2.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate preftool 0.2.0 on toolchain 0d37dca25a51fb900a402c94c8818ad1c2789e30
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate preftool 0.2.0
[INFO] finished tweaking crates.io crate preftool 0.2.0
[INFO] tweaked toml for crates.io crate preftool 0.2.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6f4beef64cf5c8f5be90e9c3a4086748ad4f4bc0aefb22c83084795e82a0b99e
[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" "6f4beef64cf5c8f5be90e9c3a4086748ad4f4bc0aefb22c83084795e82a0b99e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6f4beef64cf5c8f5be90e9c3a4086748ad4f4bc0aefb22c83084795e82a0b99e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f4beef64cf5c8f5be90e9c3a4086748ad4f4bc0aefb22c83084795e82a0b99e", kill_on_drop: false }`
[INFO] [stdout] 6f4beef64cf5c8f5be90e9c3a4086748ad4f4bc0aefb22c83084795e82a0b99e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 064bc706ab8197e1d7702dec4bb4ced34a0a52e7389e276b220e92937a7715d9
[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" "064bc706ab8197e1d7702dec4bb4ced34a0a52e7389e276b220e92937a7715d9", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling slog v2.5.2
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking arc-swap v0.4.7
[INFO] [stderr]    Compiling cargo-husky v1.5.0
[INFO] [stderr]    Compiling thread_local v1.0.1
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking log v0.4.11
[INFO] [stderr]     Checking backtrace v0.3.51
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]    Compiling aho-corasick v0.7.13
[INFO] [stderr]     Checking slog-scope v4.3.0
[INFO] [stderr]     Checking slog-stdlog v3.0.5
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling caseless v0.2.1
[INFO] [stderr]     Checking preftool v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/bind.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/bind.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 22.12s
[INFO] running `Command { std: "docker" "inspect" "064bc706ab8197e1d7702dec4bb4ced34a0a52e7389e276b220e92937a7715d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "064bc706ab8197e1d7702dec4bb4ced34a0a52e7389e276b220e92937a7715d9", kill_on_drop: false }`
[INFO] [stdout] 064bc706ab8197e1d7702dec4bb4ced34a0a52e7389e276b220e92937a7715d9