[INFO] cloning repository https://github.com/Jacobamv/Rust_File_io
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Jacobamv/Rust_File_io" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJacobamv%2FRust_File_io", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJacobamv%2FRust_File_io'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0922640d00dff91399c5aacb80298fde7b7b279a
[INFO] checking Jacobamv/Rust_File_io against master#b359ccf1b0b7b2d2c1c4932344b806e68bd053a9 for pr-105483
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJacobamv%2FRust_File_io" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Jacobamv/Rust_File_io on toolchain b359ccf1b0b7b2d2c1c4932344b806e68bd053a9
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b359ccf1b0b7b2d2c1c4932344b806e68bd053a9" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Jacobamv/Rust_File_io
[INFO] finished tweaking git repo https://github.com/Jacobamv/Rust_File_io
[INFO] tweaked toml for git repo https://github.com/Jacobamv/Rust_File_io written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/Jacobamv/Rust_File_io already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b359ccf1b0b7b2d2c1c4932344b806e68bd053a9" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:bb5b0feb4f87116a4ea905b7ff5bf5b85913db05e9f0fbc1abdd3168928d9075" "/opt/rustwide/cargo-home/bin/cargo" "+b359ccf1b0b7b2d2c1c4932344b806e68bd053a9" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fb122eb1705004e3d1a943409ca37f07b34eb375abd0f6c456dd4e8fe500b9cf
[INFO] running `Command { std: "docker" "start" "-a" "fb122eb1705004e3d1a943409ca37f07b34eb375abd0f6c456dd4e8fe500b9cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fb122eb1705004e3d1a943409ca37f07b34eb375abd0f6c456dd4e8fe500b9cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb122eb1705004e3d1a943409ca37f07b34eb375abd0f6c456dd4e8fe500b9cf", kill_on_drop: false }`
[INFO] [stdout] fb122eb1705004e3d1a943409ca37f07b34eb375abd0f6c456dd4e8fe500b9cf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:bb5b0feb4f87116a4ea905b7ff5bf5b85913db05e9f0fbc1abdd3168928d9075" "/opt/rustwide/cargo-home/bin/cargo" "+b359ccf1b0b7b2d2c1c4932344b806e68bd053a9" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6fc4345fe1287f3cd13aa94f5781a1e2dfb27e864c8a9a9b27f9bc00dac6cec0
[INFO] running `Command { std: "docker" "start" "-a" "6fc4345fe1287f3cd13aa94f5781a1e2dfb27e864c8a9a9b27f9bc00dac6cec0", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking rust_file v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/utils.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/utils.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stdout]    |                         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_file` is never used
[INFO] [stdout]   --> src/utils.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub fn create_file(a: &str) -> Result<String, String> {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `write_file` is never used
[INFO] [stdout]   --> src/utils.rs:52:8
[INFO] [stdout]    |
[INFO] [stdout] 52 | pub fn write_file(a: &str, b: &[u8]) -> Result<String, String> {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message contains an unused formatting placeholder
[INFO] [stdout]   --> src/utils.rs:17:52
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stdout]    |                                                    ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this message is not used as a format string when given without arguments, but will be in Rust 2021
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout] help: add the missing argument
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}", ...),
[INFO] [stdout]    |                                                       +++++
[INFO] [stdout] help: or add a "{}" format string to use the message literally
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("{}", "Unwrap error {}"),
[INFO] [stdout]    |                                      +++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `create_file` is never used
[INFO] [stdout]   --> src/utils.rs:27:8
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub fn create_file(a: &str) -> Result<String, String> {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `write_file` is never used
[INFO] [stdout]   --> src/utils.rs:52:8
[INFO] [stdout]    |
[INFO] [stdout] 52 | pub fn write_file(a: &str, b: &[u8]) -> Result<String, String> {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message contains an unused formatting placeholder
[INFO] [stdout]   --> src/utils.rs:17:52
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stdout]    |                                                    ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this message is not used as a format string when given without arguments, but will be in Rust 2021
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout] help: add the missing argument
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("Unwrap error {}", ...),
[INFO] [stdout]    |                                                       +++++
[INFO] [stdout] help: or add a "{}" format string to use the message literally
[INFO] [stdout]    |
[INFO] [stdout] 17 |             Result::Err(e) => panic!("{}", "Unwrap error {}"),
[INFO] [stdout]    |                                      +++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.63s
[INFO] running `Command { std: "docker" "inspect" "6fc4345fe1287f3cd13aa94f5781a1e2dfb27e864c8a9a9b27f9bc00dac6cec0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6fc4345fe1287f3cd13aa94f5781a1e2dfb27e864c8a9a9b27f9bc00dac6cec0", kill_on_drop: false }`
[INFO] [stdout] 6fc4345fe1287f3cd13aa94f5781a1e2dfb27e864c8a9a9b27f9bc00dac6cec0