[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] testing Jacobamv/Rust_File_io against master#b70888601af92f6cdc0364abab3446e418b91d36 for pr-86479
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJacobamv%2FRust_File_io" "/workspace/builds/worker-15/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-15/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Jacobamv/Rust_File_io on toolchain b70888601af92f6cdc0364abab3446e418b91d36
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b70888601af92f6cdc0364abab3446e418b91d36" "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-15/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" "+b70888601af92f6cdc0364abab3446e418b91d36" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+b70888601af92f6cdc0364abab3446e418b91d36" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d0380970b26101c4c8d7ef4909bb42b36ac28d9376761da04daac1135ad9edd9
[INFO] running `Command { std: "docker" "start" "-a" "d0380970b26101c4c8d7ef4909bb42b36ac28d9376761da04daac1135ad9edd9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d0380970b26101c4c8d7ef4909bb42b36ac28d9376761da04daac1135ad9edd9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d0380970b26101c4c8d7ef4909bb42b36ac28d9376761da04daac1135ad9edd9", kill_on_drop: false }`
[INFO] [stdout] d0380970b26101c4c8d7ef4909bb42b36ac28d9376761da04daac1135ad9edd9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+b70888601af92f6cdc0364abab3446e418b91d36" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 29fb781583ec7a110999c14e4d06f88982cf1e1ebdc458257c365e00c2e2a7c2
[INFO] running `Command { std: "docker" "start" "-a" "29fb781583ec7a110999c14e4d06f88982cf1e1ebdc458257c365e00c2e2a7c2", kill_on_drop: false }`
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling 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: function is never used: `create_file`
[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 is never used: `write_file`
[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: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]    = note: this message is not used as a format string when given without arguments, but will be in Rust 2021
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.55s
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "29fb781583ec7a110999c14e4d06f88982cf1e1ebdc458257c365e00c2e2a7c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "29fb781583ec7a110999c14e4d06f88982cf1e1ebdc458257c365e00c2e2a7c2", kill_on_drop: false }`
[INFO] [stdout] 29fb781583ec7a110999c14e4d06f88982cf1e1ebdc458257c365e00c2e2a7c2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+b70888601af92f6cdc0364abab3446e418b91d36" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 32f93939aba8dd3aa7535e9914787c4d445ac23672614b75aae7dd293abe3280
[INFO] running `Command { std: "docker" "start" "-a" "32f93939aba8dd3aa7535e9914787c4d445ac23672614b75aae7dd293abe3280", kill_on_drop: false }`
[INFO] [stderr]    Compiling 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: function is never used: `create_file`
[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 is never used: `write_file`
[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: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]    = note: this message is not used as a format string when given without arguments, but will be in Rust 2021
[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 test [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `Command { std: "docker" "inspect" "32f93939aba8dd3aa7535e9914787c4d445ac23672614b75aae7dd293abe3280", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "32f93939aba8dd3aa7535e9914787c4d445ac23672614b75aae7dd293abe3280", kill_on_drop: false }`
[INFO] [stdout] 32f93939aba8dd3aa7535e9914787c4d445ac23672614b75aae7dd293abe3280
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-15/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+b70888601af92f6cdc0364abab3446e418b91d36" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 08854bc305b67ce7cd0c14f9e496212696a456e1ef7dd681d4bc3f725a0fe86e
[INFO] running `Command { std: "docker" "start" "-a" "08854bc305b67ce7cd0c14f9e496212696a456e1ef7dd681d4bc3f725a0fe86e", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `e`
[INFO] [stderr]   --> src/utils.rs:17:25
[INFO] [stderr]    |
[INFO] [stderr] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stderr]    |                         ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `create_file`
[INFO] [stderr]   --> src/utils.rs:27:8
[INFO] [stderr]    |
[INFO] [stderr] 27 | pub fn create_file(a: &str) -> Result<String, String> {
[INFO] [stderr]    |        ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `write_file`
[INFO] [stderr]   --> src/utils.rs:52:8
[INFO] [stderr]    |
[INFO] [stderr] 52 | pub fn write_file(a: &str, b: &[u8]) -> Result<String, String> {
[INFO] [stderr]    |        ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: panic message contains an unused formatting placeholder
[INFO] [stderr]   --> src/utils.rs:17:52
[INFO] [stderr]    |
[INFO] [stderr] 17 |             Result::Err(e) => panic!("Unwrap error {}"),
[INFO] [stderr]    |                                                    ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stderr]    = note: this message is not used as a format string when given without arguments, but will be in Rust 2021
[INFO] [stderr] help: add the missing argument
[INFO] [stderr]    |
[INFO] [stderr] 17 |             Result::Err(e) => panic!("Unwrap error {}", ...),
[INFO] [stderr]    |                                                       ^^^^^
[INFO] [stderr] help: or add a "{}" format string to use the message literally
[INFO] [stderr]    |
[INFO] [stderr] 17 |             Result::Err(e) => panic!("{}", "Unwrap error {}"),
[INFO] [stderr]    |                                      ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rust_file` (bin "rust_file" test) generated 4 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust_file-7023c0855a715b6c)
[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" "08854bc305b67ce7cd0c14f9e496212696a456e1ef7dd681d4bc3f725a0fe86e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08854bc305b67ce7cd0c14f9e496212696a456e1ef7dd681d4bc3f725a0fe86e", kill_on_drop: false }`
[INFO] [stdout] 08854bc305b67ce7cd0c14f9e496212696a456e1ef7dd681d4bc3f725a0fe86e