[INFO] fetching crate tail 0.3.0...
[INFO] checking tail-0.3.0 against try#55b3f428b4fac6790b1e8492e0b91ff2d80aec7c for pr-77035
[INFO] extracting crate tail 0.3.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate tail 0.3.0 on toolchain 55b3f428b4fac6790b1e8492e0b91ff2d80aec7c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tail 0.3.0
[INFO] finished tweaking crates.io crate tail 0.3.0
[INFO] tweaked toml for crates.io crate tail 0.3.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded inotify v0.5.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 04d18cc041dcae3675c43d2bd39b2ec5aa6de5cdc663635545d9a17f7fd1e37d
[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" "04d18cc041dcae3675c43d2bd39b2ec5aa6de5cdc663635545d9a17f7fd1e37d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "04d18cc041dcae3675c43d2bd39b2ec5aa6de5cdc663635545d9a17f7fd1e37d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04d18cc041dcae3675c43d2bd39b2ec5aa6de5cdc663635545d9a17f7fd1e37d", kill_on_drop: false }`
[INFO] [stdout] 04d18cc041dcae3675c43d2bd39b2ec5aa6de5cdc663635545d9a17f7fd1e37d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+55b3f428b4fac6790b1e8492e0b91ff2d80aec7c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 089b2763da1e9096e1c5598d57cbcce71b736858c50902a1e1feffaee7ce37b1
[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" "089b2763da1e9096e1c5598d57cbcce71b736858c50902a1e1feffaee7ce37b1", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]     Checking inotify-sys v0.1.4
[INFO] [stderr]     Checking inotify v0.5.1
[INFO] [stderr]     Checking tail v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut wd = watcher.add_watch(Path::new(&file_name), WatchMask::MODIFY)
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:90:13
[INFO] [stdout]    |
[INFO] [stdout] 90 |         let mut fd = File::open(&file_name)
[INFO] [stdout]    |             ----^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut wd = watcher.add_watch(Path::new(&file_name), WatchMask::MODIFY)
[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] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:90:13
[INFO] [stdout]    |
[INFO] [stdout] 90 |         let mut fd = File::open(&file_name)
[INFO] [stdout]    |             ----^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.21s
[INFO] running `Command { std: "docker" "inspect" "089b2763da1e9096e1c5598d57cbcce71b736858c50902a1e1feffaee7ce37b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "089b2763da1e9096e1c5598d57cbcce71b736858c50902a1e1feffaee7ce37b1", kill_on_drop: false }`
[INFO] [stdout] 089b2763da1e9096e1c5598d57cbcce71b736858c50902a1e1feffaee7ce37b1