[INFO] updating cached repository VaclavStebra/rust-book-references-and-borrowing
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/VaclavStebra/rust-book-references-and-borrowing
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/VaclavStebra/rust-book-references-and-borrowing" "work/ex/pr-56896/sources/master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980/gh/VaclavStebra/rust-book-references-and-borrowing"`
[INFO] [stderr] Cloning into 'work/ex/pr-56896/sources/master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980/gh/VaclavStebra/rust-book-references-and-borrowing'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/VaclavStebra/rust-book-references-and-borrowing" "work/ex/pr-56896/sources/try#bad365140e1e8233b42b21af70a407f14ce5fec5/gh/VaclavStebra/rust-book-references-and-borrowing"`
[INFO] [stderr] Cloning into 'work/ex/pr-56896/sources/try#bad365140e1e8233b42b21af70a407f14ce5fec5/gh/VaclavStebra/rust-book-references-and-borrowing'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 6a69d6a3a909d36b8b69bc865641a6b3053066d0
[INFO] sha for GitHub repo VaclavStebra/rust-book-references-and-borrowing: 6a69d6a3a909d36b8b69bc865641a6b3053066d0
[INFO] validating manifest of VaclavStebra/rust-book-references-and-borrowing on toolchain master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+adbfec229ce07ff4b2a7bf2d6dec2d13cb224980-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of VaclavStebra/rust-book-references-and-borrowing on toolchain try#bad365140e1e8233b42b21af70a407f14ce5fec5
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+bad365140e1e8233b42b21af70a407f14ce5fec5-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] finished frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] frobbed toml for VaclavStebra/rust-book-references-and-borrowing written to work/ex/pr-56896/sources/master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980/gh/VaclavStebra/rust-book-references-and-borrowing/Cargo.toml
[INFO] started frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] finished frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] frobbed toml for VaclavStebra/rust-book-references-and-borrowing written to work/ex/pr-56896/sources/try#bad365140e1e8233b42b21af70a407f14ce5fec5/gh/VaclavStebra/rust-book-references-and-borrowing/Cargo.toml
[INFO] crate VaclavStebra/rust-book-references-and-borrowing has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+adbfec229ce07ff4b2a7bf2d6dec2d13cb224980-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+bad365140e1e8233b42b21af70a407f14ce5fec5-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking VaclavStebra/rust-book-references-and-borrowing against master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980 for pr-56896
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56896/worker-7/master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56896/sources/master#adbfec229ce07ff4b2a7bf2d6dec2d13cb224980/gh/VaclavStebra/rust-book-references-and-borrowing:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+adbfec229ce07ff4b2a7bf2d6dec2d13cb224980-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] f4a6360b2aff1490d236d390a25f6b9b9ffb6bd22f3766b216fd5cadeeec8bfb
[INFO] running `"docker" "start" "-a" "f4a6360b2aff1490d236d390a25f6b9b9ffb6bd22f3766b216fd5cadeeec8bfb"`
[INFO] [stderr]     Checking rust-book-references-and-borrowing v0.1.0 (/opt/crater/workdir)
[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: consider using `_r1` instead
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[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: consider using `_r1` instead
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.52s
[INFO] running `"docker" "inspect" "f4a6360b2aff1490d236d390a25f6b9b9ffb6bd22f3766b216fd5cadeeec8bfb"`
[INFO] running `"docker" "rm" "-f" "f4a6360b2aff1490d236d390a25f6b9b9ffb6bd22f3766b216fd5cadeeec8bfb"`
[INFO] [stdout] f4a6360b2aff1490d236d390a25f6b9b9ffb6bd22f3766b216fd5cadeeec8bfb