[INFO] cloning repository https://github.com/frisky5/learning_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/frisky5/learning_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffrisky5%2Flearning_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffrisky5%2Flearning_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 86eca4705c79e76939c61d12f9a6a8f0d2130079
[INFO] testing frisky5/learning_rust against beta-2022-04-10 for beta-1.61-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffrisky5%2Flearning_rust" "/workspace/builds/worker-18/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-18/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/frisky5/learning_rust on toolchain beta-2022-04-10
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/frisky5/learning_rust
[INFO] finished tweaking git repo https://github.com/frisky5/learning_rust
[INFO] tweaked toml for git repo https://github.com/frisky5/learning_rust written to /workspace/builds/worker-18/source/Cargo.toml
[INFO] crate git repo https://github.com/frisky5/learning_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-04-10" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bea42c3d437b03ceb520adcfb12a55791beb5e5703e5d613a472e540780d3ce1
[INFO] running `Command { std: "docker" "start" "-a" "bea42c3d437b03ceb520adcfb12a55791beb5e5703e5d613a472e540780d3ce1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bea42c3d437b03ceb520adcfb12a55791beb5e5703e5d613a472e540780d3ce1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bea42c3d437b03ceb520adcfb12a55791beb5e5703e5d613a472e540780d3ce1", kill_on_drop: false }`
[INFO] [stdout] bea42c3d437b03ceb520adcfb12a55791beb5e5703e5d613a472e540780d3ce1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b0378212b8ee8121d5abe45216578f4f5f6159d823d82477769e5646a60d15af
[INFO] running `Command { std: "docker" "start" "-a" "b0378212b8ee8121d5abe45216578f4f5f6159d823d82477769e5646a60d15af", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling learning_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::env::var`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::env::var;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let variable_4: u8 = 129; // this is a scalar type, unsigned int of 8 bit
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let variable_4: i32 = 654654654; // this is shadowing, we can change data type of the same variable name with shadowing
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let variable_4: usize = 123123123; // this variable type is unsigned arch size (32 bit or 64 bit cpu)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let variable_4: isize = 123123123; // this variable type is singed arch size (32 bit or 64 bit cpu)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let variable_4: f64 = 65134.16465846; // this is floating point
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let variable_4: bool = false; // this is boolean type of true and false
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let variable_4 = 'F'; // this is character type, four bytes in size and represents a Unicode Scalar
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `variable_7` is never read
[INFO] [stdout]   --> src/main.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let mut variable_7 = 30;
[INFO] [stdout]    |             ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 45 |     io::stdin().read_line(&mut user_input); // this will wait for the user to enter text and press enter (new line), user_input is passed...
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.58s
[INFO] running `Command { std: "docker" "inspect" "b0378212b8ee8121d5abe45216578f4f5f6159d823d82477769e5646a60d15af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b0378212b8ee8121d5abe45216578f4f5f6159d823d82477769e5646a60d15af", kill_on_drop: false }`
[INFO] [stdout] b0378212b8ee8121d5abe45216578f4f5f6159d823d82477769e5646a60d15af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b97e8bdcd0dbc575e19e1b0f8700afe2406c0eda4bcd2d21417770876ca08794
[INFO] running `Command { std: "docker" "start" "-a" "b97e8bdcd0dbc575e19e1b0f8700afe2406c0eda4bcd2d21417770876ca08794", kill_on_drop: false }`
[INFO] [stderr]    Compiling learning_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::env::var`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::env::var;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let variable_4: u8 = 129; // this is a scalar type, unsigned int of 8 bit
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let variable_4: i32 = 654654654; // this is shadowing, we can change data type of the same variable name with shadowing
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let variable_4: usize = 123123123; // this variable type is unsigned arch size (32 bit or 64 bit cpu)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let variable_4: isize = 123123123; // this variable type is singed arch size (32 bit or 64 bit cpu)
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let variable_4: f64 = 65134.16465846; // this is floating point
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let variable_4: bool = false; // this is boolean type of true and false
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `variable_4`
[INFO] [stdout]   --> src/main.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let variable_4 = 'F'; // this is character type, four bytes in size and represents a Unicode Scalar
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `variable_7` is never read
[INFO] [stdout]   --> src/main.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 67 |     let mut variable_7 = 30;
[INFO] [stdout]    |             ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 45 |     io::stdin().read_line(&mut user_input); // this will wait for the user to enter text and press enter (new line), user_input is passed...
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.39s
[INFO] [stderr]   Executable unittests src/main.rs (/opt/rustwide/target/debug/deps/learning_rust-2ae0c7e3721b852b)
[INFO] running `Command { std: "docker" "inspect" "b97e8bdcd0dbc575e19e1b0f8700afe2406c0eda4bcd2d21417770876ca08794", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b97e8bdcd0dbc575e19e1b0f8700afe2406c0eda4bcd2d21417770876ca08794", kill_on_drop: false }`
[INFO] [stdout] b97e8bdcd0dbc575e19e1b0f8700afe2406c0eda4bcd2d21417770876ca08794
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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=warn" "-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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-04-10" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 21c5ae0ad6179a52e21e88b72aa6749bd23575176ddb57f8b252054e12be5cef
[INFO] running `Command { std: "docker" "start" "-a" "21c5ae0ad6179a52e21e88b72aa6749bd23575176ddb57f8b252054e12be5cef", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: unused import: `std::env::var`
[INFO] [stdout] 
[INFO] [stderr]  --> src/main.rs:1:5
[INFO] [stdout] running 0 tests
[INFO] [stderr]   |
[INFO] [stdout] 
[INFO] [stderr] 1 | use std::env::var;
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let variable_4: u8 = 129; // this is a scalar type, unsigned int of 8 bit
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:33:9
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let variable_4: i32 = 654654654; // this is shadowing, we can change data type of the same variable name with shadowing
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:34:9
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let variable_4: usize = 123123123; // this variable type is unsigned arch size (32 bit or 64 bit cpu)
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     let variable_4: isize = 123123123; // this variable type is singed arch size (32 bit or 64 bit cpu)
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:36:9
[INFO] [stderr]    |
[INFO] [stderr] 36 |     let variable_4: f64 = 65134.16465846; // this is floating point
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let variable_4: bool = false; // this is boolean type of true and false
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `variable_4`
[INFO] [stderr]   --> src/main.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 |     let variable_4 = 'F'; // this is character type, four bytes in size and represents a Unicode Scalar
[INFO] [stderr]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_variable_4`
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `variable_7` is never read
[INFO] [stderr]   --> src/main.rs:67:13
[INFO] [stderr]    |
[INFO] [stderr] 67 |     let mut variable_7 = 30;
[INFO] [stderr]    |             ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:45:5
[INFO] [stderr]    |
[INFO] [stderr] 45 |     io::stdin().read_line(&mut user_input); // this will wait for the user to enter text and press enter (new line), user_input is passed...
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: `learning_rust` (bin "learning_rust" test) generated 10 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.24s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/learning_rust-2ae0c7e3721b852b)
[INFO] running `Command { std: "docker" "inspect" "21c5ae0ad6179a52e21e88b72aa6749bd23575176ddb57f8b252054e12be5cef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21c5ae0ad6179a52e21e88b72aa6749bd23575176ddb57f8b252054e12be5cef", kill_on_drop: false }`
[INFO] [stdout] 21c5ae0ad6179a52e21e88b72aa6749bd23575176ddb57f8b252054e12be5cef