[INFO] fetching crate maybe-single 0.12.0...
[INFO] checking maybe-single-0.12.0 against try#82acd1d76add2232e19c1f0feb250d2a19ec6efe for pr-81213
[INFO] extracting crate maybe-single 0.12.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate maybe-single 0.12.0 on toolchain 82acd1d76add2232e19c1f0feb250d2a19ec6efe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate maybe-single 0.12.0
[INFO] finished tweaking crates.io crate maybe-single 0.12.0
[INFO] tweaked toml for crates.io crate maybe-single 0.12.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c66bb52bea7a1c00f3072258bbc92820bd91d81f8a1412363a9bbac6b0afa596
[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" "c66bb52bea7a1c00f3072258bbc92820bd91d81f8a1412363a9bbac6b0afa596", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c66bb52bea7a1c00f3072258bbc92820bd91d81f8a1412363a9bbac6b0afa596", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c66bb52bea7a1c00f3072258bbc92820bd91d81f8a1412363a9bbac6b0afa596", kill_on_drop: false }`
[INFO] [stdout] c66bb52bea7a1c00f3072258bbc92820bd91d81f8a1412363a9bbac6b0afa596
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+82acd1d76add2232e19c1f0feb250d2a19ec6efe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 342fba18bb40533f40198213a2ee32a2678bd819e85debe46039d5348686fd13
[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" "342fba18bb40533f40198213a2ee32a2678bd819e85debe46039d5348686fd13", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling log v0.4.13
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]     Checking bytes v0.5.6
[INFO] [stderr]     Checking getrandom v0.1.16
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking parking_lot v0.10.2
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking maybe-single v0.12.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::ops::Deref`
[INFO] [stdout]  --> src/nio.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::ops::Deref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `RwLockReadGuard`, `RwLockWriteGuard`
[INFO] [stdout]  --> src/nio.rs:6:34
[INFO] [stdout]   |
[INFO] [stdout] 6 | use parking_lot::{Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
[INFO] [stdout]   |                                  ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `read_lock`
[INFO] [stdout]   --> src/lib.rs:77:5
[INFO] [stdout]    |
[INFO] [stdout] 77 |     read_lock: Option<RwLockReadGuard<'a, ()>>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `write_lock`
[INFO] [stdout]   --> src/lib.rs:78:5
[INFO] [stdout]    |
[INFO] [stdout] 78 |     write_lock: Option<RwLockWriteGuard<'a, ()>>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]    Compiling syn v1.0.59
[INFO] [stderr]    Compiling tokio-macros v0.2.6
[INFO] [stderr]     Checking tokio v0.2.24
[INFO] [stdout] error[E0277]: the trait bound `read_dir::DirEntry: std::sealed::Sealed` is not satisfied
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.24/src/fs/read_dir.rs:240:6
[INFO] [stdout]     |
[INFO] [stdout] 240 | impl DirEntryExt for DirEntry {
[INFO] [stdout]     |      ^^^^^^^^^^^ the trait `std::sealed::Sealed` is not implemented for `read_dir::DirEntry`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tokio`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "342fba18bb40533f40198213a2ee32a2678bd819e85debe46039d5348686fd13", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "342fba18bb40533f40198213a2ee32a2678bd819e85debe46039d5348686fd13", kill_on_drop: false }`
[INFO] [stdout] 342fba18bb40533f40198213a2ee32a2678bd819e85debe46039d5348686fd13