[INFO] cloning repository https://github.com/agoodstart/intro-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/agoodstart/intro-to-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fagoodstart%2Fintro-to-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fagoodstart%2Fintro-to-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 45542451ece434e48ca265358f49f298d6614c7a
[INFO] testing agoodstart/intro-to-rust against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fagoodstart%2Fintro-to-rust" "/workspace/builds/worker-119/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-119/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/agoodstart/intro-to-rust on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/agoodstart/intro-to-rust
[INFO] finished tweaking git repo https://github.com/agoodstart/intro-to-rust
[INFO] tweaked toml for git repo https://github.com/agoodstart/intro-to-rust written to /workspace/builds/worker-119/source/Cargo.toml
[INFO] crate git repo https://github.com/agoodstart/intro-to-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 730356c41313abb01363d1c9c1cc61f3de5c9f52dc6ace63472ca0ba92f6a7fa
[INFO] running `Command { std: "docker" "start" "-a" "730356c41313abb01363d1c9c1cc61f3de5c9f52dc6ace63472ca0ba92f6a7fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "730356c41313abb01363d1c9c1cc61f3de5c9f52dc6ace63472ca0ba92f6a7fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "730356c41313abb01363d1c9c1cc61f3de5c9f52dc6ace63472ca0ba92f6a7fa", kill_on_drop: false }`
[INFO] [stdout] 730356c41313abb01363d1c9c1cc61f3de5c9f52dc6ace63472ca0ba92f6a7fa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0377ce40f66bbf5bc03e790637a69d865f4382a567b27f8ae58ec0a932e6a3c0
[INFO] running `Command { std: "docker" "start" "-a" "0377ce40f66bbf5bc03e790637a69d865f4382a567b27f8ae58ec0a932e6a3c0", kill_on_drop: false }`
[INFO] [stderr]    Compiling intro-to-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/error_handling_part_two.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let f = File::open("hello.txt")?;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file`
[INFO] [stdout]   --> src/error_handling_part_two.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `short_func`
[INFO] [stdout]   --> src/error_handling_part_two.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn short_func() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `even_shorter`
[INFO] [stdout]   --> src/error_handling_part_two.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn even_shorter() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `shortest`
[INFO] [stdout]   --> src/error_handling_part_two.rs:41:4
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn shortest() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 49 |     error_handling_part_two::run();
[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: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.55s
[INFO] running `Command { std: "docker" "inspect" "0377ce40f66bbf5bc03e790637a69d865f4382a567b27f8ae58ec0a932e6a3c0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0377ce40f66bbf5bc03e790637a69d865f4382a567b27f8ae58ec0a932e6a3c0", kill_on_drop: false }`
[INFO] [stdout] 0377ce40f66bbf5bc03e790637a69d865f4382a567b27f8ae58ec0a932e6a3c0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 28cc1fc59cdeb50367637763ef05aa1fedc952733c00319e8a25e36342ad8bd1
[INFO] running `Command { std: "docker" "start" "-a" "28cc1fc59cdeb50367637763ef05aa1fedc952733c00319e8a25e36342ad8bd1", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling intro-to-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]  --> src/error_handling_part_two.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let f = File::open("hello.txt")?;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `read_username_from_file`
[INFO] [stdout]   --> src/error_handling_part_two.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `short_func`
[INFO] [stdout]   --> src/error_handling_part_two.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn short_func() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `even_shorter`
[INFO] [stdout]   --> src/error_handling_part_two.rs:35:4
[INFO] [stdout]    |
[INFO] [stdout] 35 | fn even_shorter() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `shortest`
[INFO] [stdout]   --> src/error_handling_part_two.rs:41:4
[INFO] [stdout]    |
[INFO] [stdout] 41 | fn shortest() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:49:5
[INFO] [stdout]    |
[INFO] [stdout] 49 |     error_handling_part_two::run();
[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] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 13.88s
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "28cc1fc59cdeb50367637763ef05aa1fedc952733c00319e8a25e36342ad8bd1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28cc1fc59cdeb50367637763ef05aa1fedc952733c00319e8a25e36342ad8bd1", kill_on_drop: false }`
[INFO] [stdout] 28cc1fc59cdeb50367637763ef05aa1fedc952733c00319e8a25e36342ad8bd1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-119/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] fed6d45d205ec6f2faf428fa0a9c1fc478c927829311cbd9369b4ed0402ad160
[INFO] running `Command { std: "docker" "start" "-a" "fed6d45d205ec6f2faf428fa0a9c1fc478c927829311cbd9369b4ed0402ad160", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/error_handling_part_two.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let f = File::open("hello.txt")?;
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `read_username_from_file`
[INFO] [stderr]   --> src/error_handling_part_two.rs:12:4
[INFO] [stderr]    |
[INFO] [stderr] 12 | fn read_username_from_file() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `short_func`
[INFO] [stderr]   --> src/error_handling_part_two.rs:28:4
[INFO] [stderr]    |
[INFO] [stderr] 28 | fn short_func() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `even_shorter`
[INFO] [stderr]   --> src/error_handling_part_two.rs:35:4
[INFO] [stderr]    |
[INFO] [stderr] 35 | fn even_shorter() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `shortest`
[INFO] [stderr]   --> src/error_handling_part_two.rs:41:4
[INFO] [stderr]    |
[INFO] [stderr] 41 | fn shortest() -> Result<String, io::Error> {
[INFO] [stderr]    |    ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:49:5
[INFO] [stderr]    |
[INFO] [stderr] 49 |     error_handling_part_two::run();
[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: `intro-to-rust` (bin "intro-to-rust" test) generated 6 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/intro_to_rust-acf62dfce51b51b9)
[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" "fed6d45d205ec6f2faf428fa0a9c1fc478c927829311cbd9369b4ed0402ad160", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fed6d45d205ec6f2faf428fa0a9c1fc478c927829311cbd9369b4ed0402ad160", kill_on_drop: false }`
[INFO] [stdout] fed6d45d205ec6f2faf428fa0a9c1fc478c927829311cbd9369b4ed0402ad160