[INFO] fetching crate thread_io 0.2.0...
[INFO] checking thread_io-0.2.0 against master#2748a9fd93dd1a00a4521f4f16de5befbf77f6cd for pr-62262-1
[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 2748a9fd93dd1a00a4521f4f16de5befbf77f6cd
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "read-manifest" "--manifest-path" "Cargo.toml"`
[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 `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "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" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 168ee96e577b7a3b59024afb15425a70b32426dfb582af80d3b8a3dc90d1ac59
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "168ee96e577b7a3b59024afb15425a70b32426dfb582af80d3b8a3dc90d1ac59"`
[INFO] [stderr]     Checking crossbeam v0.6.0
[INFO] [stderr]     Checking thread_io v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> tests/read.rs:64:25
[INFO] [stderr]    |
[INFO] [stderr] 64 |                     let mut rdr = Reader::new(text, rdr_block_size, ::std::usize::MAX);
[INFO] [stderr]    |                         ----^^^
[INFO] [stderr]    |                         |
[INFO] [stderr]    |                         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> tests/read.rs:68:25
[INFO] [stderr]    |
[INFO] [stderr] 68 |                     let mut rdr = Reader::new(text, rdr_block_size, ::std::usize::MAX);
[INFO] [stderr]    |                         ----^^^
[INFO] [stderr]    |                         |
[INFO] [stderr]    |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> tests/read.rs:94:17
[INFO] [stderr]    |
[INFO] [stderr] 94 |             let mut rdr = Reader::new(text, channel_bufsize, len / channel_bufsize);
[INFO] [stderr]    |                 ----^^^
[INFO] [stderr]    |                 |
[INFO] [stderr]    |                 help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> tests/write.rs:61:21
[INFO] [stderr]    |
[INFO] [stderr] 61 |                 let mut w = writer_init_finish(
[INFO] [stderr]    |                     ----^
[INFO] [stderr]    |                     |
[INFO] [stderr]    |                     help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.34s
[INFO] running `"docker" "inspect" "168ee96e577b7a3b59024afb15425a70b32426dfb582af80d3b8a3dc90d1ac59"`
[INFO] running `"docker" "rm" "-f" "168ee96e577b7a3b59024afb15425a70b32426dfb582af80d3b8a3dc90d1ac59"`
[INFO] [stdout] 168ee96e577b7a3b59024afb15425a70b32426dfb582af80d3b8a3dc90d1ac59