[INFO] fetching crate tac 0.2.3...
[INFO] testing tac-0.2.3 against try#eafdee2dfae8c2233b74f98b123308be7ccefcc6 for pr-79296
[INFO] extracting crate tac 0.2.3 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate tac 0.2.3 on toolchain eafdee2dfae8c2233b74f98b123308be7ccefcc6
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tac 0.2.3
[INFO] finished tweaking crates.io crate tac 0.2.3
[INFO] tweaked toml for crates.io crate tac 0.2.3 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded memmap v0.5.2
[INFO] [stderr]   Downloaded uuid v0.4.0
[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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9bc64db0405496eb530f6bfc6f0eaf0f051123f0f8baea89da3746baeb432d48
[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" "9bc64db0405496eb530f6bfc6f0eaf0f051123f0f8baea89da3746baeb432d48", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9bc64db0405496eb530f6bfc6f0eaf0f051123f0f8baea89da3746baeb432d48", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9bc64db0405496eb530f6bfc6f0eaf0f051123f0f8baea89da3746baeb432d48", kill_on_drop: false }`
[INFO] [stdout] 9bc64db0405496eb530f6bfc6f0eaf0f051123f0f8baea89da3746baeb432d48
[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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e1b7374b8c6d29cd9f7e27982d682dd43d9f9f826350433a6a8ff562e8acf09
[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" "6e1b7374b8c6d29cd9f7e27982d682dd43d9f9f826350433a6a8ff562e8acf09", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling memmap v0.5.2
[INFO] [stderr]    Compiling rand v0.3.23
[INFO] [stderr]    Compiling uuid v0.4.0
[INFO] [stderr]    Compiling tac v0.2.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Write` is imported redundantly
[INFO] [stdout]   --> src/main.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 5  | use std::io::{StdoutLock, Write};
[INFO] [stdout]    |                           ----- the item `Write` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 72 |     use std::io::Write;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:64:16
[INFO] [stdout]    |
[INFO] [stdout] 64 | fn print_bytes(mut stdout: &mut StdoutLock, bytes: &[u8]) {
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.78s
[INFO] running `Command { std: "docker" "inspect" "6e1b7374b8c6d29cd9f7e27982d682dd43d9f9f826350433a6a8ff562e8acf09", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e1b7374b8c6d29cd9f7e27982d682dd43d9f9f826350433a6a8ff562e8acf09", kill_on_drop: false }`
[INFO] [stdout] 6e1b7374b8c6d29cd9f7e27982d682dd43d9f9f826350433a6a8ff562e8acf09
[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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dca72a6aef3543f8f6595181b8691eaa025f592987676b562c67838b0286c5bc
[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" "dca72a6aef3543f8f6595181b8691eaa025f592987676b562c67838b0286c5bc", kill_on_drop: false }`
[INFO] [stderr]    Compiling tac v0.2.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Write` is imported redundantly
[INFO] [stdout]   --> src/main.rs:72:9
[INFO] [stdout]    |
[INFO] [stdout] 5  | use std::io::{StdoutLock, Write};
[INFO] [stdout]    |                           ----- the item `Write` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 72 |     use std::io::Write;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:64:16
[INFO] [stdout]    |
[INFO] [stdout] 64 | fn print_bytes(mut stdout: &mut StdoutLock, bytes: &[u8]) {
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.55s
[INFO] running `Command { std: "docker" "inspect" "dca72a6aef3543f8f6595181b8691eaa025f592987676b562c67838b0286c5bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dca72a6aef3543f8f6595181b8691eaa025f592987676b562c67838b0286c5bc", kill_on_drop: false }`
[INFO] [stdout] dca72a6aef3543f8f6595181b8691eaa025f592987676b562c67838b0286c5bc
[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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 367683f4256e779d845f06540eab9b2820135a81f2369994c3a3088b9d37b452
[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" "367683f4256e779d845f06540eab9b2820135a81f2369994c3a3088b9d37b452", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: the item `Write` is imported redundantly
[INFO] [stdout] running 0 tests
[INFO] [stderr]   --> src/main.rs:72:9
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stderr] 5  | use std::io::{StdoutLock, Write};
[INFO] [stdout] 
[INFO] [stderr]    |                           ----- the item `Write` is already imported here
[INFO] [stderr] ...
[INFO] [stderr] 72 |     use std::io::Write;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:64:16
[INFO] [stderr]    |
[INFO] [stderr] 64 | fn print_bytes(mut stdout: &mut StdoutLock, bytes: &[u8]) {
[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: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/tac-0b6129469f55b1a3
[INFO] running `Command { std: "docker" "inspect" "367683f4256e779d845f06540eab9b2820135a81f2369994c3a3088b9d37b452", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "367683f4256e779d845f06540eab9b2820135a81f2369994c3a3088b9d37b452", kill_on_drop: false }`
[INFO] [stdout] 367683f4256e779d845f06540eab9b2820135a81f2369994c3a3088b9d37b452