[INFO] cloning repository https://github.com/jsimmons/concurrency
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jsimmons/concurrency" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjsimmons%2Fconcurrency", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjsimmons%2Fconcurrency'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0bddc198fbfc1f6fdd45249b8c2c65f3c99fe59b
[INFO] checking jsimmons/concurrency against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjsimmons%2Fconcurrency" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jsimmons/concurrency on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jsimmons/concurrency
[INFO] finished tweaking git repo https://github.com/jsimmons/concurrency
[INFO] tweaked toml for git repo https://github.com/jsimmons/concurrency written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/jsimmons/concurrency already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d9e12252a717538f5ff54db98df6f879d066dcdd6170faac4b351c6e0e808f33
[INFO] running `Command { std: "docker" "start" "-a" "d9e12252a717538f5ff54db98df6f879d066dcdd6170faac4b351c6e0e808f33", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d9e12252a717538f5ff54db98df6f879d066dcdd6170faac4b351c6e0e808f33", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d9e12252a717538f5ff54db98df6f879d066dcdd6170faac4b351c6e0e808f33", kill_on_drop: false }`
[INFO] [stdout] d9e12252a717538f5ff54db98df6f879d066dcdd6170faac4b351c6e0e808f33
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3571412e002f6a2e816e342fab4362997aff234633a3e5d5975bc7f3ff698b70
[INFO] running `Command { std: "docker" "start" "-a" "3571412e002f6a2e816e342fab4362997aff234633a3e5d5975bc7f3ff698b70", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]     Checking concurrency v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/main.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | use libc::{self, setpriority, PRIO_PROCESS};
[INFO] [stdout]    |            ^^^^ the item `libc` is already defined by prelude
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/main.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | use libc::{self, setpriority, PRIO_PROCESS};
[INFO] [stdout]    |            ^^^^ the item `libc` is already defined by prelude
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/main.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | impl SingleThreadUniverse {
[INFO] [stdout]    | ------------------------- associated function in this implementation
[INFO] [stdout] 26 |     fn new(num_fast: usize, num_slow: usize) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/main.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | impl SingleThreadUniverse {
[INFO] [stdout]    | ------------------------- associated function in this implementation
[INFO] [stdout] 26 |     fn new(num_fast: usize, num_slow: usize) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.22s
[INFO] running `Command { std: "docker" "inspect" "3571412e002f6a2e816e342fab4362997aff234633a3e5d5975bc7f3ff698b70", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3571412e002f6a2e816e342fab4362997aff234633a3e5d5975bc7f3ff698b70", kill_on_drop: false }`
[INFO] [stdout] 3571412e002f6a2e816e342fab4362997aff234633a3e5d5975bc7f3ff698b70
[INFO] checking jsimmons/concurrency against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjsimmons%2Fconcurrency" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jsimmons/concurrency on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jsimmons/concurrency
[INFO] finished tweaking git repo https://github.com/jsimmons/concurrency
[INFO] tweaked toml for git repo https://github.com/jsimmons/concurrency written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/jsimmons/concurrency already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5eaf0698fab08aff2e72d8d2ceb86b6a1894cbf71cef53b3be7195908b639274
[INFO] running `Command { std: "docker" "start" "-a" "5eaf0698fab08aff2e72d8d2ceb86b6a1894cbf71cef53b3be7195908b639274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5eaf0698fab08aff2e72d8d2ceb86b6a1894cbf71cef53b3be7195908b639274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5eaf0698fab08aff2e72d8d2ceb86b6a1894cbf71cef53b3be7195908b639274", kill_on_drop: false }`
[INFO] [stdout] 5eaf0698fab08aff2e72d8d2ceb86b6a1894cbf71cef53b3be7195908b639274
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 477e6b2483150e9215892a7fcac64799c46cbc2c629fa96e50d592d3b22b938f
[INFO] running `Command { std: "docker" "start" "-a" "477e6b2483150e9215892a7fcac64799c46cbc2c629fa96e50d592d3b22b938f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]     Checking concurrency v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/main.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | use libc::{self, setpriority, PRIO_PROCESS};
[INFO] [stdout]    |            ^^^^ the item `libc` is already defined by prelude
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/main.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | use libc::{self, setpriority, PRIO_PROCESS};
[INFO] [stdout]    |            ^^^^ the item `libc` is already defined by prelude
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/main.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | impl SingleThreadUniverse {
[INFO] [stdout]    | ------------------------- associated function in this implementation
[INFO] [stdout] 26 |     fn new(num_fast: usize, num_slow: usize) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/main.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | impl SingleThreadUniverse {
[INFO] [stdout]    | ------------------------- associated function in this implementation
[INFO] [stdout] 26 |     fn new(num_fast: usize, num_slow: usize) -> Self {
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[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` profile [unoptimized + debuginfo] target(s) in 1.14s
[INFO] running `Command { std: "docker" "inspect" "477e6b2483150e9215892a7fcac64799c46cbc2c629fa96e50d592d3b22b938f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "477e6b2483150e9215892a7fcac64799c46cbc2c629fa96e50d592d3b22b938f", kill_on_drop: false }`
[INFO] [stdout] 477e6b2483150e9215892a7fcac64799c46cbc2c629fa96e50d592d3b22b938f