[INFO] crate buffer_io 1.0.3 is already in cache
[INFO] testing buffer_io-1.0.3 against beta-2020-07-24 for beta-1.46-1
[INFO] extracting crate buffer_io 1.0.3 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate buffer_io 1.0.3 on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", 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-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "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] 2e99b7a56a2515ac055c8b0006665598ec7dab9210786469c875ad071a82bbde
[INFO] running `Command { std: "docker" "start" "-a" "2e99b7a56a2515ac055c8b0006665598ec7dab9210786469c875ad071a82bbde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e99b7a56a2515ac055c8b0006665598ec7dab9210786469c875ad071a82bbde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e99b7a56a2515ac055c8b0006665598ec7dab9210786469c875ad071a82bbde", kill_on_drop: false }`
[INFO] [stdout] 2e99b7a56a2515ac055c8b0006665598ec7dab9210786469c875ad071a82bbde
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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=warn" "-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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8f2cb7b2236cde1058861ee7d7dfb6cc21460bca2a74cbac7fe8285657a292b6
[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" "8f2cb7b2236cde1058861ee7d7dfb6cc21460bca2a74cbac7fe8285657a292b6", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling buffer_io v1.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `b` is never read
[INFO] [stdout]    --> src/lib.rs:211:17
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.67s
[INFO] running `Command { std: "docker" "inspect" "8f2cb7b2236cde1058861ee7d7dfb6cc21460bca2a74cbac7fe8285657a292b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8f2cb7b2236cde1058861ee7d7dfb6cc21460bca2a74cbac7fe8285657a292b6", kill_on_drop: false }`
[INFO] [stdout] 8f2cb7b2236cde1058861ee7d7dfb6cc21460bca2a74cbac7fe8285657a292b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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=warn" "-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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4d8e8f5272602127ba3d960f9d8d34e7da77e3519a20e127835dc2dde098f50a
[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" "4d8e8f5272602127ba3d960f9d8d34e7da77e3519a20e127835dc2dde098f50a", kill_on_drop: false }`
[INFO] [stderr]    Compiling buffer_io v1.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `b` is never read
[INFO] [stdout]    --> src/lib.rs:211:17
[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: value assigned to `b` is never read
[INFO] [stdout]    --> src/lib.rs:211:17
[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] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.32s
[INFO] running `Command { std: "docker" "inspect" "4d8e8f5272602127ba3d960f9d8d34e7da77e3519a20e127835dc2dde098f50a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d8e8f5272602127ba3d960f9d8d34e7da77e3519a20e127835dc2dde098f50a", kill_on_drop: false }`
[INFO] [stdout] 4d8e8f5272602127ba3d960f9d8d34e7da77e3519a20e127835dc2dde098f50a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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=warn" "-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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 768237ecca9b117401c27b3aac0f10fd1d1e7ab4204f2d05c566eb9e6d09ad0a
[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" "768237ecca9b117401c27b3aac0f10fd1d1e7ab4204f2d05c566eb9e6d09ad0a", kill_on_drop: false }`
[INFO] [stderr] warning: value assigned to `b` is never read
[INFO] [stderr]    --> src/lib.rs:211:17
[INFO] [stderr]     |
[INFO] [stderr] 211 |             let mut b: u8 = 0;
[INFO] [stderr]     |                 ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]     = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stderr] warning: value assigned to `b` is never read
[INFO] [stdout] running 1 test
[INFO] [stderr]    --> src/lib.rs:211:17
[INFO] [stdout] test tests::it_works ... ok
[INFO] [stderr]     |
[INFO] [stdout] 
[INFO] [stderr] 211 |             let mut b: u8 = 0;
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stderr]     |                 ^^^^^
[INFO] [stdout] 
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]     = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.06s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/buffer_io-3c55a85b9fa89f70
[INFO] [stderr]    Doc-tests buffer_io
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "768237ecca9b117401c27b3aac0f10fd1d1e7ab4204f2d05c566eb9e6d09ad0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "768237ecca9b117401c27b3aac0f10fd1d1e7ab4204f2d05c566eb9e6d09ad0a", kill_on_drop: false }`
[INFO] [stdout] 768237ecca9b117401c27b3aac0f10fd1d1e7ab4204f2d05c566eb9e6d09ad0a