[INFO] cloning repository https://github.com/Ermain-12/Introduction-to-Rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Ermain-12/Introduction-to-Rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 19db755187092c11f3f3ea13092682fc7bc92786
[INFO] testing Ermain-12/Introduction-to-Rust against master#a77da2d454e6caa227a85b16410b95f93495e7e0 for pr-91031
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FErmain-12%2FIntroduction-to-Rust" "/workspace/builds/worker-40/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-40/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Ermain-12/Introduction-to-Rust on toolchain a77da2d454e6caa227a85b16410b95f93495e7e0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Ermain-12/Introduction-to-Rust
[INFO] finished tweaking git repo https://github.com/Ermain-12/Introduction-to-Rust
[INFO] tweaked toml for git repo https://github.com/Ermain-12/Introduction-to-Rust written to /workspace/builds/worker-40/source/Cargo.toml
[INFO] crate git repo https://github.com/Ermain-12/Introduction-to-Rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] adc3a136d59982116fb6a5173f43c7e6d79ede833076954a1d524c10bb2eb8b8
[INFO] running `Command { std: "docker" "start" "-a" "adc3a136d59982116fb6a5173f43c7e6d79ede833076954a1d524c10bb2eb8b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "adc3a136d59982116fb6a5173f43c7e6d79ede833076954a1d524c10bb2eb8b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "adc3a136d59982116fb6a5173f43c7e6d79ede833076954a1d524c10bb2eb8b8", kill_on_drop: false }`
[INFO] [stdout] adc3a136d59982116fb6a5173f43c7e6d79ede833076954a1d524c10bb2eb8b8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 88c7c9a380a994bb91c90f32c7e0d2d9b44d4b3ddac4cd192fad6b48d698de89
[INFO] running `Command { std: "docker" "start" "-a" "88c7c9a380a994bb91c90f32c7e0d2d9b44d4b3ddac4cd192fad6b48d698de89", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.40
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling lazy_static v1.0.0
[INFO] [stderr]    Compiling ucd-util v0.1.1
[INFO] [stderr]    Compiling regex v1.0.0
[INFO] [stderr]    Compiling utf8-ranges v1.0.0
[INFO] [stderr]    Compiling unreachable v1.0.0
[INFO] [stderr]    Compiling thread_local v0.3.5
[INFO] [stderr]    Compiling regex-syntax v0.6.0
[INFO] [stderr]    Compiling memchr v2.0.1
[INFO] [stderr]    Compiling time v0.1.40
[INFO] [stderr]    Compiling aho-corasick v0.6.4
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    let mut twenty_one = my_vec.pop();
[INFO] [stdout]    |        ----^^^^^^^^^^
[INFO] [stdout]    |        |
[INFO] [stdout]    |        help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 30.41s
[INFO] running `Command { std: "docker" "inspect" "88c7c9a380a994bb91c90f32c7e0d2d9b44d4b3ddac4cd192fad6b48d698de89", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88c7c9a380a994bb91c90f32c7e0d2d9b44d4b3ddac4cd192fad6b48d698de89", kill_on_drop: false }`
[INFO] [stdout] 88c7c9a380a994bb91c90f32c7e0d2d9b44d4b3ddac4cd192fad6b48d698de89
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 329e9f977af062eca39c0076d40b86309d7a9fb7898f185778f0c07cfdf6b5ed
[INFO] running `Command { std: "docker" "start" "-a" "329e9f977af062eca39c0076d40b86309d7a9fb7898f185778f0c07cfdf6b5ed", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 |    let mut twenty_one = my_vec.pop();
[INFO] [stdout]    |        ----^^^^^^^^^^
[INFO] [stdout]    |        |
[INFO] [stdout]    |        help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 2.27s
[INFO] running `Command { std: "docker" "inspect" "329e9f977af062eca39c0076d40b86309d7a9fb7898f185778f0c07cfdf6b5ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "329e9f977af062eca39c0076d40b86309d7a9fb7898f185778f0c07cfdf6b5ed", kill_on_drop: false }`
[INFO] [stdout] 329e9f977af062eca39c0076d40b86309d7a9fb7898f185778f0c07cfdf6b5ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] e205d450f9d8604824fb2c045d4e06829e9656074f579fff53e99afa2d5b0bd4
[INFO] running `Command { std: "docker" "start" "-a" "e205d450f9d8604824fb2c045d4e06829e9656074f579fff53e99afa2d5b0bd4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:27:8
[INFO] [stderr]    |
[INFO] [stderr] 27 |    let mut twenty_one = my_vec.pop();
[INFO] [stderr]    |        ----^^^^^^^^^^
[INFO] [stderr]    |        |
[INFO] [stderr]    |        help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `hello_world` (bin "hello_world" test) generated 1 warning
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.18s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/hello_world-88e7c5edad7ec615)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "e205d450f9d8604824fb2c045d4e06829e9656074f579fff53e99afa2d5b0bd4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e205d450f9d8604824fb2c045d4e06829e9656074f579fff53e99afa2d5b0bd4", kill_on_drop: false }`
[INFO] [stdout] e205d450f9d8604824fb2c045d4e06829e9656074f579fff53e99afa2d5b0bd4