[INFO] fetching crate thread_io 0.2.0...
[INFO] checking thread_io-0.2.0 against master#e1beee4992ad4b235fc700bf7af1ee86f894ea53 for pr-74130
[INFO] extracting crate thread_io 0.2.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate thread_io 0.2.0 on toolchain e1beee4992ad4b235fc700bf7af1ee86f894ea53
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate thread_io 0.2.0
[INFO] finished tweaking crates.io crate thread_io 0.2.0
[INFO] tweaked toml for crates.io crate thread_io 0.2.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9890a439d12101193e00a814b424abdf907fed28122b4fccd72c1eb7a2fb175f
[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" "9890a439d12101193e00a814b424abdf907fed28122b4fccd72c1eb7a2fb175f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9890a439d12101193e00a814b424abdf907fed28122b4fccd72c1eb7a2fb175f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9890a439d12101193e00a814b424abdf907fed28122b4fccd72c1eb7a2fb175f", kill_on_drop: false }`
[INFO] [stdout] 9890a439d12101193e00a814b424abdf907fed28122b4fccd72c1eb7a2fb175f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "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] 3f3e4fa9faca7604b057b1dc486a1be9cb0d424eb79d6e1667feb528dcf61a54
[INFO] running `Command { std: "docker" "start" "-a" "3f3e4fa9faca7604b057b1dc486a1be9cb0d424eb79d6e1667feb528dcf61a54", kill_on_drop: false }`
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking rand v0.6.5
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking crossbeam-deque v0.6.3
[INFO] [stderr]     Checking parking_lot_core v0.4.0
[INFO] [stderr]     Checking parking_lot v0.7.1
[INFO] [stderr]     Checking crossbeam v0.6.0
[INFO] [stderr]     Checking thread_io v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/write.rs:61:21
[INFO] [stdout]    |
[INFO] [stdout] 61 |                 let mut w = writer_init_finish(
[INFO] [stdout]    |                     ----^
[INFO] [stdout]    |                     |
[INFO] [stdout]    |                     help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/read.rs:64:25
[INFO] [stdout]    |
[INFO] [stdout] 64 |                     let mut rdr = Reader::new(text, rdr_block_size, ::std::usize::MAX);
[INFO] [stdout]    |                         ----^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/read.rs:68:25
[INFO] [stdout]    |
[INFO] [stdout] 68 |                     let mut rdr = Reader::new(text, rdr_block_size, ::std::usize::MAX);
[INFO] [stdout]    |                         ----^^^
[INFO] [stdout]    |                         |
[INFO] [stdout]    |                         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/read.rs:94:17
[INFO] [stdout]    |
[INFO] [stdout] 94 |             let mut rdr = Reader::new(text, channel_bufsize, len / channel_bufsize);
[INFO] [stdout]    |                 ----^^^
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 6.05s
[INFO] running `Command { std: "docker" "inspect" "3f3e4fa9faca7604b057b1dc486a1be9cb0d424eb79d6e1667feb528dcf61a54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f3e4fa9faca7604b057b1dc486a1be9cb0d424eb79d6e1667feb528dcf61a54", kill_on_drop: false }`
[INFO] [stdout] 3f3e4fa9faca7604b057b1dc486a1be9cb0d424eb79d6e1667feb528dcf61a54