[INFO] cloning repository https://github.com/VaclavStebra/rust-book-references-and-borrowing
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/VaclavStebra/rust-book-references-and-borrowing" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVaclavStebra%2Frust-book-references-and-borrowing", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVaclavStebra%2Frust-book-references-and-borrowing'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6a69d6a3a909d36b8b69bc865641a6b3053066d0
[INFO] testing VaclavStebra/rust-book-references-and-borrowing against beta-2021-09-08 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVaclavStebra%2Frust-book-references-and-borrowing" "/workspace/builds/worker-17/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-17/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/VaclavStebra/rust-book-references-and-borrowing on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/VaclavStebra/rust-book-references-and-borrowing
[INFO] finished tweaking git repo https://github.com/VaclavStebra/rust-book-references-and-borrowing
[INFO] tweaked toml for git repo https://github.com/VaclavStebra/rust-book-references-and-borrowing written to /workspace/builds/worker-17/source/Cargo.toml
[INFO] crate git repo https://github.com/VaclavStebra/rust-book-references-and-borrowing already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4d2549428893159d54702a482e05e134404bdbeb679d098111813448c7cbffe8
[INFO] running `Command { std: "docker" "start" "-a" "4d2549428893159d54702a482e05e134404bdbeb679d098111813448c7cbffe8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4d2549428893159d54702a482e05e134404bdbeb679d098111813448c7cbffe8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d2549428893159d54702a482e05e134404bdbeb679d098111813448c7cbffe8", kill_on_drop: false }`
[INFO] [stdout] 4d2549428893159d54702a482e05e134404bdbeb679d098111813448c7cbffe8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1bc0f78dce500f9be369a2f583abe5ffc3c3f89b3d3302c27ac929c18c5bfa5e
[INFO] running `Command { std: "docker" "start" "-a" "1bc0f78dce500f9be369a2f583abe5ffc3c3f89b3d3302c27ac929c18c5bfa5e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling rust-book-references-and-borrowing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let r1 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.47s
[INFO] running `Command { std: "docker" "inspect" "1bc0f78dce500f9be369a2f583abe5ffc3c3f89b3d3302c27ac929c18c5bfa5e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1bc0f78dce500f9be369a2f583abe5ffc3c3f89b3d3302c27ac929c18c5bfa5e", kill_on_drop: false }`
[INFO] [stdout] 1bc0f78dce500f9be369a2f583abe5ffc3c3f89b3d3302c27ac929c18c5bfa5e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+beta-2021-09-08" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4f60cf0b7662506c9aa6c1f15e477202a60e0d77f420b9b8ba46ecd91e3f9e0b
[INFO] running `Command { std: "docker" "start" "-a" "4f60cf0b7662506c9aa6c1f15e477202a60e0d77f420b9b8ba46ecd91e3f9e0b", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling rust-book-references-and-borrowing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let r1 = &mut s2;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.57s
[INFO] running `Command { std: "docker" "inspect" "4f60cf0b7662506c9aa6c1f15e477202a60e0d77f420b9b8ba46ecd91e3f9e0b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f60cf0b7662506c9aa6c1f15e477202a60e0d77f420b9b8ba46ecd91e3f9e0b", kill_on_drop: false }`
[INFO] [stdout] 4f60cf0b7662506c9aa6c1f15e477202a60e0d77f420b9b8ba46ecd91e3f9e0b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+beta-2021-09-08" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 1c5db5d7a6d3d688f5c1045d77eb564f3c58dc39bc711c8a4fc4580644b22bb5
[INFO] running `Command { std: "docker" "start" "-a" "1c5db5d7a6d3d688f5c1045d77eb564f3c58dc39bc711c8a4fc4580644b22bb5", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]   --> src/main.rs:20:9
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let r1 = &mut s2;
[INFO] [stderr]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-book-references-and-borrowing` (bin "rust-book-references-and-borrowing" test) generated 1 warning
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust_book_references_and_borrowing-ca95b141ea36ca6d)
[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" "1c5db5d7a6d3d688f5c1045d77eb564f3c58dc39bc711c8a4fc4580644b22bb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c5db5d7a6d3d688f5c1045d77eb564f3c58dc39bc711c8a4fc4580644b22bb5", kill_on_drop: false }`
[INFO] [stdout] 1c5db5d7a6d3d688f5c1045d77eb564f3c58dc39bc711c8a4fc4580644b22bb5