[INFO] cloning repository https://github.com/fahrenkrug/rust_learn_book_errors
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fahrenkrug/rust_learn_book_errors" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_errors", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_errors'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] aa959a404d3e1af5bf3df0465fa974898c211764
[INFO] testing fahrenkrug/rust_learn_book_errors against try#ecabaf78506b7a4668d42dc20268c086b93f0fad for pr-87041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffahrenkrug%2Frust_learn_book_errors" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/fahrenkrug/rust_learn_book_errors on toolchain ecabaf78506b7a4668d42dc20268c086b93f0fad
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/fahrenkrug/rust_learn_book_errors
[INFO] finished tweaking git repo https://github.com/fahrenkrug/rust_learn_book_errors
[INFO] tweaked toml for git repo https://github.com/fahrenkrug/rust_learn_book_errors written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/fahrenkrug/rust_learn_book_errors already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0961e480aeba5185493228b8eeba7525a4b23144a93cf82c83fbd54b22d8f970
[INFO] running `Command { std: "docker" "start" "-a" "0961e480aeba5185493228b8eeba7525a4b23144a93cf82c83fbd54b22d8f970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0961e480aeba5185493228b8eeba7525a4b23144a93cf82c83fbd54b22d8f970", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0961e480aeba5185493228b8eeba7525a4b23144a93cf82c83fbd54b22d8f970", kill_on_drop: false }`
[INFO] [stdout] 0961e480aeba5185493228b8eeba7525a4b23144a93cf82c83fbd54b22d8f970
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fece4e83e2ece029f9aa0809a956890ba09c14ab27b94c147992bd3e6ef5a4f9
[INFO] running `Command { std: "docker" "start" "-a" "fece4e83e2ece029f9aa0809a956890ba09c14ab27b94c147992bd3e6ef5a4f9", kill_on_drop: false }`
[INFO] [stderr]    Compiling errors v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:65:9
[INFO] [stdout]    |
[INFO] [stdout] 65 |     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/main.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 | 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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.74s
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "fece4e83e2ece029f9aa0809a956890ba09c14ab27b94c147992bd3e6ef5a4f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fece4e83e2ece029f9aa0809a956890ba09c14ab27b94c147992bd3e6ef5a4f9", kill_on_drop: false }`
[INFO] [stdout] fece4e83e2ece029f9aa0809a956890ba09c14ab27b94c147992bd3e6ef5a4f9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 84bfa17cadfed3e41accc68e984efd569f80db5ba398c79b11861ca0f597ba92
[INFO] running `Command { std: "docker" "start" "-a" "84bfa17cadfed3e41accc68e984efd569f80db5ba398c79b11861ca0f597ba92", kill_on_drop: false }`
[INFO] [stderr]    Compiling errors v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:65:9
[INFO] [stdout]    |
[INFO] [stdout] 65 |     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/main.rs:69:4
[INFO] [stdout]    |
[INFO] [stdout] 69 | 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.60s
[INFO] running `Command { std: "docker" "inspect" "84bfa17cadfed3e41accc68e984efd569f80db5ba398c79b11861ca0f597ba92", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84bfa17cadfed3e41accc68e984efd569f80db5ba398c79b11861ca0f597ba92", kill_on_drop: false }`
[INFO] [stdout] 84bfa17cadfed3e41accc68e984efd569f80db5ba398c79b11861ca0f597ba92
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "+ecabaf78506b7a4668d42dc20268c086b93f0fad" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 8c8ec7d99d7ce8d2e79819240944c47950d607ab4a927d7e0852158438396e5b
[INFO] running `Command { std: "docker" "start" "-a" "8c8ec7d99d7ce8d2e79819240944c47950d607ab4a927d7e0852158438396e5b", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/main.rs:65:9
[INFO] [stderr]    |
[INFO] [stderr] 65 |     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/main.rs:69:4
[INFO] [stderr]    |
[INFO] [stderr] 69 | 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: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/errors-529b2646a83a38d8)
[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" "8c8ec7d99d7ce8d2e79819240944c47950d607ab4a927d7e0852158438396e5b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c8ec7d99d7ce8d2e79819240944c47950d607ab4a927d7e0852158438396e5b", kill_on_drop: false }`
[INFO] [stdout] 8c8ec7d99d7ce8d2e79819240944c47950d607ab4a927d7e0852158438396e5b