[INFO] fetching crate maybe-single 0.12.0...
[INFO] checking maybe-single-0.12.0 against master#bd0bacc694d7d8175804bb6f690cb846bfa4a9ee for pr-71665
[INFO] extracting crate maybe-single 0.12.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate maybe-single 0.12.0 on toolchain bd0bacc694d7d8175804bb6f690cb846bfa4a9ee
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-14/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+bd0bacc694d7d8175804bb6f690cb846bfa4a9ee" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f53b309a235fe6a66483c6625db9afe5aa30e5f9ec5b280409a2bcb48f850b37
[INFO] running `"docker" "start" "-a" "f53b309a235fe6a66483c6625db9afe5aa30e5f9ec5b280409a2bcb48f850b37"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling proc-macro2 v1.0.12
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking smallvec v1.4.0
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking arc-swap v0.4.6
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking fnv v1.0.6
[INFO] [stderr]     Checking once_cell v1.3.1
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]    Compiling quote v1.0.4
[INFO] [stderr]    Compiling syn v1.0.19
[INFO] [stderr]     Checking net2 v0.2.34
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking parking_lot v0.10.2
[INFO] [stderr]     Checking mio v0.6.22
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking maybe-single v0.12.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `std::ops::Deref`
[INFO] [stderr]  --> src/nio.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::ops::Deref;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `RwLockReadGuard`, `RwLockWriteGuard`
[INFO] [stderr]  --> src/nio.rs:6:34
[INFO] [stderr]   |
[INFO] [stderr] 6 | use parking_lot::{Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
[INFO] [stderr]   |                                  ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `read_lock`
[INFO] [stderr]   --> src/lib.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     read_lock: Option<RwLockReadGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `write_lock`
[INFO] [stderr]   --> src/lib.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     write_lock: Option<RwLockWriteGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]     Checking tokio v0.2.20
[INFO] [stderr] warning: unused import: `std::ops::Deref`
[INFO] [stderr]  --> src/nio.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::ops::Deref;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `RwLockReadGuard`, `RwLockWriteGuard`
[INFO] [stderr]  --> src/nio.rs:6:34
[INFO] [stderr]   |
[INFO] [stderr] 6 | use parking_lot::{Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
[INFO] [stderr]   |                                  ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Rng`, `thread_rng`
[INFO] [stderr]   --> src/nio.rs:87:16
[INFO] [stderr]    |
[INFO] [stderr] 87 |     use rand::{thread_rng, Rng};
[INFO] [stderr]    |                ^^^^^^^^^^  ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::thread::sleep`
[INFO] [stderr]   --> src/nio.rs:88:9
[INFO] [stderr]    |
[INFO] [stderr] 88 |     use std::thread::sleep;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::time::Duration`
[INFO] [stderr]   --> src/nio.rs:89:9
[INFO] [stderr]    |
[INFO] [stderr] 89 |     use std::time::Duration;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `tokio::time::Instant`
[INFO] [stderr]   --> src/nio.rs:90:9
[INFO] [stderr]    |
[INFO] [stderr] 90 |     use tokio::time::Instant;
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::future::Future`
[INFO] [stderr]    --> src/lib.rs:119:9
[INFO] [stderr]     |
[INFO] [stderr] 119 |     use std::future::Future;
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::pin::Pin`
[INFO] [stderr]    --> src/lib.rs:120:9
[INFO] [stderr]     |
[INFO] [stderr] 120 |     use std::pin::Pin;
[INFO] [stderr]     |         ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `read_lock`
[INFO] [stderr]   --> src/lib.rs:77:5
[INFO] [stderr]    |
[INFO] [stderr] 77 |     read_lock: Option<RwLockReadGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `write_lock`
[INFO] [stderr]   --> src/lib.rs:78:5
[INFO] [stderr]    |
[INFO] [stderr] 78 |     write_lock: Option<RwLockWriteGuard<'a, ()>>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 10 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 30.61s
[INFO] running `"docker" "inspect" "f53b309a235fe6a66483c6625db9afe5aa30e5f9ec5b280409a2bcb48f850b37"`
[INFO] running `"docker" "rm" "-f" "f53b309a235fe6a66483c6625db9afe5aa30e5f9ec5b280409a2bcb48f850b37"`
[INFO] [stdout] f53b309a235fe6a66483c6625db9afe5aa30e5f9ec5b280409a2bcb48f850b37