[INFO] cloning repository https://github.com/abharun/my-rust-course
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/abharun/my-rust-course" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabharun%2Fmy-rust-course", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabharun%2Fmy-rust-course'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 93107510cbcb832c778a029189adbb3cb68ed086
[INFO] checking abharun/my-rust-course against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabharun%2Fmy-rust-course" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/abharun/my-rust-course 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/abharun/my-rust-course
[INFO] finished tweaking git repo https://github.com/abharun/my-rust-course
[INFO] tweaked toml for git repo https://github.com/abharun/my-rust-course written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/abharun/my-rust-course 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-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 4e51e72c75fcf6277886b7c01cb508682244b613cb15b8b8d68977dd6083cf2c
[INFO] running `Command { std: "docker" "start" "-a" "4e51e72c75fcf6277886b7c01cb508682244b613cb15b8b8d68977dd6083cf2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4e51e72c75fcf6277886b7c01cb508682244b613cb15b8b8d68977dd6083cf2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e51e72c75fcf6277886b7c01cb508682244b613cb15b8b8d68977dd6083cf2c", kill_on_drop: false }`
[INFO] [stdout] 4e51e72c75fcf6277886b7c01cb508682244b613cb15b8b8d68977dd6083cf2c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] bcfaa14532e960a2551b5024f53934907d3e9befd86ceb865fc277a0ff5f6ac1
[INFO] running `Command { std: "docker" "start" "-a" "bcfaa14532e960a2551b5024f53934907d3e9befd86ceb865fc277a0ff5f6ac1", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.79
[INFO] [stderr]     Checking futures-core v0.3.30
[INFO] [stderr]     Checking futures-sink v0.3.30
[INFO] [stderr]     Checking mio v0.8.11
[INFO] [stderr]     Checking event-listener v5.2.0
[INFO] [stderr]     Checking futures-channel v0.3.30
[INFO] [stderr]     Checking event-listener-strategy v0.5.0
[INFO] [stderr]     Checking async-channel v2.2.0
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.53
[INFO] [stderr]    Compiling futures-macro v0.3.30
[INFO] [stderr]    Compiling tokio-macros v2.2.0
[INFO] [stderr]     Checking tokio v1.36.0
[INFO] [stderr]     Checking futures-util v0.3.30
[INFO] [stderr]     Checking futures-executor v0.3.30
[INFO] [stderr]     Checking futures v0.3.30
[INFO] [stderr]     Checking my-rust-course v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/functions/mythreading.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rand::{self, Rng};
[INFO] [stdout]   |            ^^^^ the item `rand` 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 `rand` is imported redundantly
[INFO] [stdout]  --> src/functions/mythreading.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rand::{self, Rng};
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 13.97s
[INFO] running `Command { std: "docker" "inspect" "bcfaa14532e960a2551b5024f53934907d3e9befd86ceb865fc277a0ff5f6ac1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bcfaa14532e960a2551b5024f53934907d3e9befd86ceb865fc277a0ff5f6ac1", kill_on_drop: false }`
[INFO] [stdout] bcfaa14532e960a2551b5024f53934907d3e9befd86ceb865fc277a0ff5f6ac1
[INFO] checking abharun/my-rust-course against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabharun%2Fmy-rust-course" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/abharun/my-rust-course 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/abharun/my-rust-course
[INFO] finished tweaking git repo https://github.com/abharun/my-rust-course
[INFO] tweaked toml for git repo https://github.com/abharun/my-rust-course written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/abharun/my-rust-course 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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 48f38861728d23b2c3713217c3e085f688057c7b907fe582f0f2bd2b78ce972d
[INFO] running `Command { std: "docker" "start" "-a" "48f38861728d23b2c3713217c3e085f688057c7b907fe582f0f2bd2b78ce972d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "48f38861728d23b2c3713217c3e085f688057c7b907fe582f0f2bd2b78ce972d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48f38861728d23b2c3713217c3e085f688057c7b907fe582f0f2bd2b78ce972d", kill_on_drop: false }`
[INFO] [stdout] 48f38861728d23b2c3713217c3e085f688057c7b907fe582f0f2bd2b78ce972d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 35f90af7ea905fee953f8efade6df71cb1db25d95b03a0d109c56b7732c865e1
[INFO] running `Command { std: "docker" "start" "-a" "35f90af7ea905fee953f8efade6df71cb1db25d95b03a0d109c56b7732c865e1", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.79
[INFO] [stderr]     Checking futures-core v0.3.30
[INFO] [stderr]     Checking futures-sink v0.3.30
[INFO] [stderr]     Checking mio v0.8.11
[INFO] [stderr]     Checking event-listener v5.2.0
[INFO] [stderr]     Checking futures-channel v0.3.30
[INFO] [stderr]     Checking event-listener-strategy v0.5.0
[INFO] [stderr]     Checking async-channel v2.2.0
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.53
[INFO] [stderr]    Compiling futures-macro v0.3.30
[INFO] [stderr]    Compiling tokio-macros v2.2.0
[INFO] [stderr]     Checking tokio v1.36.0
[INFO] [stderr]     Checking futures-util v0.3.30
[INFO] [stderr]     Checking futures-executor v0.3.30
[INFO] [stderr]     Checking futures v0.3.30
[INFO] [stderr]     Checking my-rust-course v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/functions/mythreading.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rand::{self, Rng};
[INFO] [stdout]   |            ^^^^ the item `rand` 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 `rand` is imported redundantly
[INFO] [stdout]  --> src/functions/mythreading.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | use rand::{self, Rng};
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 13.00s
[INFO] running `Command { std: "docker" "inspect" "35f90af7ea905fee953f8efade6df71cb1db25d95b03a0d109c56b7732c865e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35f90af7ea905fee953f8efade6df71cb1db25d95b03a0d109c56b7732c865e1", kill_on_drop: false }`
[INFO] [stdout] 35f90af7ea905fee953f8efade6df71cb1db25d95b03a0d109c56b7732c865e1