[INFO] fetching crate tail 0.3.0...
[INFO] testing tail-0.3.0 against 1.47.0 for beta-1.48-1
[INFO] extracting crate tail 0.3.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate tail 0.3.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "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-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2d793749e3c00325019eb26dbb92222a74d197c65f6f6017aa65bd5db1d7eb14
[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" "2d793749e3c00325019eb26dbb92222a74d197c65f6f6017aa65bd5db1d7eb14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2d793749e3c00325019eb26dbb92222a74d197c65f6f6017aa65bd5db1d7eb14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d793749e3c00325019eb26dbb92222a74d197c65f6f6017aa65bd5db1d7eb14", kill_on_drop: false }`
[INFO] [stdout] 2d793749e3c00325019eb26dbb92222a74d197c65f6f6017aa65bd5db1d7eb14
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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=warn" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] de9b83ea54eb4739289c5c4aff8bdfdd6a932eaf3fff96e3d8f7f75e70cd2831
[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" "de9b83ea54eb4739289c5c4aff8bdfdd6a932eaf3fff96e3d8f7f75e70cd2831", kill_on_drop: false }`
[INFO] [stderr]    Compiling inotify v0.5.1
[INFO] [stderr]    Compiling 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.06s
[INFO] running `Command { std: "docker" "inspect" "de9b83ea54eb4739289c5c4aff8bdfdd6a932eaf3fff96e3d8f7f75e70cd2831", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "de9b83ea54eb4739289c5c4aff8bdfdd6a932eaf3fff96e3d8f7f75e70cd2831", kill_on_drop: false }`
[INFO] [stdout] de9b83ea54eb4739289c5c4aff8bdfdd6a932eaf3fff96e3d8f7f75e70cd2831
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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=warn" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c78afb5036d310edcddfcbd88cdc00d730c0857bd32e954fa760139a826d5624
[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" "c78afb5036d310edcddfcbd88cdc00d730c0857bd32e954fa760139a826d5624", kill_on_drop: false }`
[INFO] [stderr]    Compiling 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.52s
[INFO] running `Command { std: "docker" "inspect" "c78afb5036d310edcddfcbd88cdc00d730c0857bd32e954fa760139a826d5624", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c78afb5036d310edcddfcbd88cdc00d730c0857bd32e954fa760139a826d5624", kill_on_drop: false }`
[INFO] [stdout] c78afb5036d310edcddfcbd88cdc00d730c0857bd32e954fa760139a826d5624
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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=warn" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 276aa4fd29867afea315d3278779511f1ed4387844cafc94b7ba4118eccaf761
[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" "276aa4fd29867afea315d3278779511f1ed4387844cafc94b7ba4118eccaf761", kill_on_drop: false }`
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:88:13
[INFO] [stderr]    |
[INFO] [stderr] 88 |         let mut wd = watcher.add_watch(Path::new(&file_name), WatchMask::MODIFY)
[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: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:90:13
[INFO] [stderr]    |
[INFO] [stderr] 90 |         let mut fd = File::open(&file_name)
[INFO] [stderr]    |             ----^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/tail-0a58bd537562e8d5
[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] [stderr]      Running /opt/rustwide/target/debug/deps/tail-d5fced9825b46fd4
[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] [stderr]    Doc-tests tail
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs - BackwardsReader (line 23) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- src/lib.rs - BackwardsReader (line 23) stdout ----
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `BackwardsReader`
[INFO] [stdout]  --> src/lib.rs:25:18
[INFO] [stdout]   |
[INFO] [stdout] 4 | let mut reader = BackwardsReader::new(10, &mut writer);
[INFO] [stdout]   |                  ^^^^^^^^^^^^^^^ use of undeclared type or module `BackwardsReader`
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `BufWriter`
[INFO] [stdout]  --> src/lib.rs:24:18
[INFO] [stdout]   |
[INFO] [stdout] 3 | let mut writer = BufWriter::new(std::io::stdout());
[INFO] [stdout]   |                  ^^^^^^^^^ not found in this scope
[INFO] [stdout]   |
[INFO] [stdout] help: consider importing this struct
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::BufWriter;
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0433`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     src/lib.rs - BackwardsReader (line 23)
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass '--doc'
[INFO] running `Command { std: "docker" "inspect" "276aa4fd29867afea315d3278779511f1ed4387844cafc94b7ba4118eccaf761", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "276aa4fd29867afea315d3278779511f1ed4387844cafc94b7ba4118eccaf761", kill_on_drop: false }`
[INFO] [stdout] 276aa4fd29867afea315d3278779511f1ed4387844cafc94b7ba4118eccaf761
