[INFO] fetching crate maybe-single 0.12.0...
[INFO] checking maybe-single-0.12.0 against try#72f88fc4e9458f89516a0b8b0868f3718aec5b47 for pr-74989
[INFO] extracting crate maybe-single 0.12.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate maybe-single 0.12.0 on toolchain 72f88fc4e9458f89516a0b8b0868f3718aec5b47
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+72f88fc4e9458f89516a0b8b0868f3718aec5b47" "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-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+72f88fc4e9458f89516a0b8b0868f3718aec5b47" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+72f88fc4e9458f89516a0b8b0868f3718aec5b47" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+72f88fc4e9458f89516a0b8b0868f3718aec5b47" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1f6867bc3f0bcc8aef9dc0330960fd2184ec402893bbba2011cfcfd201ad2faa
[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" "1f6867bc3f0bcc8aef9dc0330960fd2184ec402893bbba2011cfcfd201ad2faa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1f6867bc3f0bcc8aef9dc0330960fd2184ec402893bbba2011cfcfd201ad2faa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1f6867bc3f0bcc8aef9dc0330960fd2184ec402893bbba2011cfcfd201ad2faa", kill_on_drop: false }`
[INFO] [stdout] 1f6867bc3f0bcc8aef9dc0330960fd2184ec402893bbba2011cfcfd201ad2faa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+72f88fc4e9458f89516a0b8b0868f3718aec5b47" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8cd59bd4d0b9f2e8e4ad15bf9c0ea3063f3e18ded8360439f4d0ce17a564d32
[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" "b8cd59bd4d0b9f2e8e4ad15bf9c0ea3063f3e18ded8360439f4d0ce17a564d32", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.77
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling proc-macro2 v1.0.21
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling getrandom v0.1.15
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling syn v1.0.40
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking ppv-lite86 v0.2.9
[INFO] [stderr]     Checking futures-core v0.3.5
[INFO] [stderr]     Checking fnv v1.0.7
[INFO] [stderr]     Checking bytes v0.5.6
[INFO] [stderr]     Checking pin-project-lite v0.1.7
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking net2 v0.2.35
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[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 maybe-single v0.12.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking rand_chacha v0.2.2
[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]     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 v0.2.22
[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: unused imports: `Rng`, `thread_rng`
[INFO] [stdout]   --> src/nio.rs:87:16
[INFO] [stdout]    |
[INFO] [stdout] 87 |     use rand::{thread_rng, Rng};
[INFO] [stdout]    |                ^^^^^^^^^^  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::sleep`
[INFO] [stdout]   --> src/nio.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     use std::thread::sleep;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]   --> src/nio.rs:89:9
[INFO] [stdout]    |
[INFO] [stdout] 89 |     use std::time::Duration;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::time::Instant`
[INFO] [stdout]   --> src/nio.rs:90:9
[INFO] [stdout]    |
[INFO] [stdout] 90 |     use tokio::time::Instant;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::future::Future`
[INFO] [stdout]    --> src/lib.rs:119:9
[INFO] [stdout]     |
[INFO] [stdout] 119 |     use std::future::Future;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::pin::Pin`
[INFO] [stdout]    --> src/lib.rs:120:9
[INFO] [stdout]     |
[INFO] [stdout] 120 |     use std::pin::Pin;
[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: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 28.18s
[INFO] running `Command { std: "docker" "inspect" "b8cd59bd4d0b9f2e8e4ad15bf9c0ea3063f3e18ded8360439f4d0ce17a564d32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8cd59bd4d0b9f2e8e4ad15bf9c0ea3063f3e18ded8360439f4d0ce17a564d32", kill_on_drop: false }`
[INFO] [stdout] b8cd59bd4d0b9f2e8e4ad15bf9c0ea3063f3e18ded8360439f4d0ce17a564d32
