[INFO] fetching crate buffer_io 1.0.3...
[INFO] checking buffer_io-1.0.3 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate buffer_io 1.0.3 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate buffer_io 1.0.3 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate buffer_io 1.0.3
[INFO] finished tweaking crates.io crate buffer_io 1.0.3
[INFO] tweaked toml for crates.io crate buffer_io 1.0.3 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", 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] 0d24309897510b595bb27d753231e6a392899fcc19ed8583ce8a138cdb3b88ee
[INFO] running `Command { std: "docker" "start" "-a" "0d24309897510b595bb27d753231e6a392899fcc19ed8583ce8a138cdb3b88ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d24309897510b595bb27d753231e6a392899fcc19ed8583ce8a138cdb3b88ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d24309897510b595bb27d753231e6a392899fcc19ed8583ce8a138cdb3b88ee", kill_on_drop: false }`
[INFO] [stdout] 0d24309897510b595bb27d753231e6a392899fcc19ed8583ce8a138cdb3b88ee
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8b2908c7deb50152d3deb5a3a3f9f96d7a89f981e39c445d275268abafda5e5
[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" "b8b2908c7deb50152d3deb5a3a3f9f96d7a89f981e39c445d275268abafda5e5", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling thiserror-impl v1.0.26
[INFO] [stderr]     Checking thiserror v1.0.26
[INFO] [stderr]     Checking buffer_io v1.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `b` is never read
[INFO] [stdout]    --> src/lib.rs:211:21
[INFO] [stdout]     |
[INFO] [stdout] 211 |             let mut b: u8 = 0;
[INFO] [stdout]     |                     ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `b` is never read
[INFO] [stdout]    --> src/lib.rs:211:21
[INFO] [stdout]     |
[INFO] [stdout] 211 |             let mut b: u8 = 0;
[INFO] [stdout]     |                     ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 11.79s
[INFO] running `Command { std: "docker" "inspect" "b8b2908c7deb50152d3deb5a3a3f9f96d7a89f981e39c445d275268abafda5e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8b2908c7deb50152d3deb5a3a3f9f96d7a89f981e39c445d275268abafda5e5", kill_on_drop: false }`
[INFO] [stdout] b8b2908c7deb50152d3deb5a3a3f9f96d7a89f981e39c445d275268abafda5e5