[INFO] fetching crate rust_io 0.6.0...
[INFO] checking rust_io-0.6.0 against master#38352b01ae4af9300be03b805d6db68c45e51068 for pr-129864
[INFO] extracting crate rust_io 0.6.0 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate rust_io 0.6.0 on toolchain 38352b01ae4af9300be03b805d6db68c45e51068
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+38352b01ae4af9300be03b805d6db68c45e51068" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rust_io 0.6.0
[INFO] finished tweaking crates.io crate rust_io 0.6.0
[INFO] tweaked toml for crates.io crate rust_io 0.6.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+38352b01ae4af9300be03b805d6db68c45e51068" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 81 packages to latest compatible versions
[INFO] [stderr]       Adding async-channel v1.9.0 (available: v2.3.1)
[INFO] [stderr]       Adding event-listener v2.5.3 (available: v5.3.1)
[INFO] [stderr]       Adding linux-raw-sys v0.4.14 (available: v0.6.5)
[INFO] [stderr]       Adding wasi v0.11.0+wasi-snapshot-preview1 (available: v0.13.2+wasi-0.2.1)
[INFO] [stderr]       Adding windows-sys v0.52.0 (available: v0.59.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+38352b01ae4af9300be03b805d6db68c45e51068" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+38352b01ae4af9300be03b805d6db68c45e51068" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 763a23d07ecdc78f7b070462b52407a349463ca9dc6da4d0d9083585784b525a
[INFO] running `Command { std: "docker" "start" "-a" "763a23d07ecdc78f7b070462b52407a349463ca9dc6da4d0d9083585784b525a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "763a23d07ecdc78f7b070462b52407a349463ca9dc6da4d0d9083585784b525a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "763a23d07ecdc78f7b070462b52407a349463ca9dc6da4d0d9083585784b525a", kill_on_drop: false }`
[INFO] [stdout] 763a23d07ecdc78f7b070462b52407a349463ca9dc6da4d0d9083585784b525a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+38352b01ae4af9300be03b805d6db68c45e51068" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b52ff42e3f55fda8099e38423d6e77393c4ead0c0b20739e1e1ba0cdcc7acafd
[INFO] running `Command { std: "docker" "start" "-a" "b52ff42e3f55fda8099e38423d6e77393c4ead0c0b20739e1e1ba0cdcc7acafd", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.159
[INFO] [stderr]     Checking futures-sink v0.3.30
[INFO] [stderr]     Checking byteorder v1.5.0
[INFO] [stderr]    Compiling syn v2.0.77
[INFO] [stderr]     Checking futures-channel v0.3.30
[INFO] [stderr]     Checking getrandom v0.2.15
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]    Compiling zerocopy-derive v0.7.35
[INFO] [stderr]    Compiling futures-macro v0.3.30
[INFO] [stderr]     Checking futures-util v0.3.30
[INFO] [stderr]     Checking zerocopy v0.7.35
[INFO] [stderr]     Checking ppv-lite86 v0.2.20
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking futures-executor v0.3.30
[INFO] [stderr]     Checking futures v0.3.30
[INFO] [stderr]     Checking rust_io v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Rng` and `thread_rng`
[INFO] [stdout]  --> src/lib.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | use rand::{Rng, thread_rng};
[INFO] [stdout]   |            ^^^  ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]    --> src/lib.rs:782:29
[INFO] [stdout]     |
[INFO] [stdout] 782 |                 .map_error(|t| String::from("Error B"));
[INFO] [stdout]     |                             ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]    --> src/lib.rs:930:29
[INFO] [stdout]     |
[INFO] [stdout] 930 |                 .map_error(|t| String::from("Error B"))
[INFO] [stdout]     |                             ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.51s
[INFO] running `Command { std: "docker" "inspect" "b52ff42e3f55fda8099e38423d6e77393c4ead0c0b20739e1e1ba0cdcc7acafd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b52ff42e3f55fda8099e38423d6e77393c4ead0c0b20739e1e1ba0cdcc7acafd", kill_on_drop: false }`
[INFO] [stdout] b52ff42e3f55fda8099e38423d6e77393c4ead0c0b20739e1e1ba0cdcc7acafd