[INFO] fetching crate tail 0.3.0...
[INFO] checking tail-0.3.0 against master#7b3a7819371cef92a187e9bac8f7810ccde15216 for pr-74846
[INFO] extracting crate tail 0.3.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate tail 0.3.0 on toolchain 7b3a7819371cef92a187e9bac8f7810ccde15216
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "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-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "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] 5530dd59bffc0fbfc1b3183e7309f8113467335bee91f1ddb8c51ec7b48f24ee
[INFO] running `Command { std: "docker" "start" "-a" "5530dd59bffc0fbfc1b3183e7309f8113467335bee91f1ddb8c51ec7b48f24ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5530dd59bffc0fbfc1b3183e7309f8113467335bee91f1ddb8c51ec7b48f24ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5530dd59bffc0fbfc1b3183e7309f8113467335bee91f1ddb8c51ec7b48f24ee", kill_on_drop: false }`
[INFO] [stdout] 5530dd59bffc0fbfc1b3183e7309f8113467335bee91f1ddb8c51ec7b48f24ee
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+7b3a7819371cef92a187e9bac8f7810ccde15216" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9f2c4ca909cf8e9a035204cc7ab73f1e5db9ed5a3333d32ae6c0223eab7c9b65
[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" "9f2c4ca909cf8e9a035204cc7ab73f1e5db9ed5a3333d32ae6c0223eab7c9b65", kill_on_drop: false }`
[INFO] [stderr]     Checking futures v0.1.29
[INFO] [stderr]     Checking getopts v0.2.21
[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: 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] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.17s
[INFO] running `Command { std: "docker" "inspect" "9f2c4ca909cf8e9a035204cc7ab73f1e5db9ed5a3333d32ae6c0223eab7c9b65", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f2c4ca909cf8e9a035204cc7ab73f1e5db9ed5a3333d32ae6c0223eab7c9b65", kill_on_drop: false }`
[INFO] [stdout] 9f2c4ca909cf8e9a035204cc7ab73f1e5db9ed5a3333d32ae6c0223eab7c9b65