[INFO] fetching crate thread_io 0.2.0...
[INFO] checking thread_io-0.2.0 against master#119d2a1a98fe87d4ae6cabf12134a0ef2fb95851 for pr-75180
[INFO] extracting crate thread_io 0.2.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate thread_io 0.2.0 on toolchain 119d2a1a98fe87d4ae6cabf12134a0ef2fb95851
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+119d2a1a98fe87d4ae6cabf12134a0ef2fb95851" "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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+119d2a1a98fe87d4ae6cabf12134a0ef2fb95851" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+119d2a1a98fe87d4ae6cabf12134a0ef2fb95851" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+119d2a1a98fe87d4ae6cabf12134a0ef2fb95851" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4a8b3a7d689207719c41d4e110ebef47da99f14565796495afe3eb556862348a
[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" "4a8b3a7d689207719c41d4e110ebef47da99f14565796495afe3eb556862348a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a8b3a7d689207719c41d4e110ebef47da99f14565796495afe3eb556862348a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a8b3a7d689207719c41d4e110ebef47da99f14565796495afe3eb556862348a", kill_on_drop: false }`
[INFO] [stdout] 4a8b3a7d689207719c41d4e110ebef47da99f14565796495afe3eb556862348a
[INFO] running `Command { std: "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" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+119d2a1a98fe87d4ae6cabf12134a0ef2fb95851" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7cb8c65f51510ce31054ebe4ea9cf5c038591c310b5bab7550ae3e1281e0bc92
[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" "7cb8c65f51510ce31054ebe4ea9cf5c038591c310b5bab7550ae3e1281e0bc92", kill_on_drop: false }`
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]     Checking parking_lot_core v0.4.0
[INFO] [stderr]     Checking arrayvec v0.4.12
[INFO] [stderr]     Checking parking_lot v0.7.1
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking crossbeam-deque v0.6.3
[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/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: 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: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.50s
[INFO] running `Command { std: "docker" "inspect" "7cb8c65f51510ce31054ebe4ea9cf5c038591c310b5bab7550ae3e1281e0bc92", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7cb8c65f51510ce31054ebe4ea9cf5c038591c310b5bab7550ae3e1281e0bc92", kill_on_drop: false }`
[INFO] [stdout] 7cb8c65f51510ce31054ebe4ea9cf5c038591c310b5bab7550ae3e1281e0bc92