[INFO] updating cached repository robbystk/rust-by-the-book
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/robbystk/rust-by-the-book
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/robbystk/rust-by-the-book" "work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/robbystk/rust-by-the-book'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/robbystk/rust-by-the-book" "work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/robbystk/rust-by-the-book'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b2120be5dc3c77b3f9df768ed82cad8b55111ffb
[INFO] sha for GitHub repo robbystk/rust-by-the-book: b2120be5dc3c77b3f9df768ed82cad8b55111ffb
[INFO] validating manifest of robbystk/rust-by-the-book on toolchain master#f66e4697ae286985ddefc53c3a047614568458bb
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of robbystk/rust-by-the-book on toolchain try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing robbystk/rust-by-the-book
[INFO] finished frobbing robbystk/rust-by-the-book
[INFO] frobbed toml for robbystk/rust-by-the-book written to work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/robbystk/rust-by-the-book/Cargo.toml
[INFO] started frobbing robbystk/rust-by-the-book
[INFO] finished frobbing robbystk/rust-by-the-book
[INFO] frobbed toml for robbystk/rust-by-the-book written to work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/robbystk/rust-by-the-book/Cargo.toml
[INFO] crate robbystk/rust-by-the-book has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking robbystk/rust-by-the-book against try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a for pr-58592
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58592/worker-6/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/robbystk/rust-by-the-book:/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" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 392836b0a7752bf3f767f9a3a08500db61af0cb834aab72b0a88dbf689f71bfc
[INFO] running `"docker" "start" "-a" "392836b0a7752bf3f767f9a3a08500db61af0cb834aab72b0a88dbf689f71bfc"`
[INFO] [stderr]     Checking errors v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/main.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stderr]   |         ^ help: consider prefixing with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]  --> src/main.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let f = File::open("hello.txt").expect("Failed to open hello.txt");
[INFO] [stderr]   |         ^ help: consider prefixing with an underscore: `_f`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `"docker" "inspect" "392836b0a7752bf3f767f9a3a08500db61af0cb834aab72b0a88dbf689f71bfc"`
[INFO] running `"docker" "rm" "-f" "392836b0a7752bf3f767f9a3a08500db61af0cb834aab72b0a88dbf689f71bfc"`
[INFO] [stdout] 392836b0a7752bf3f767f9a3a08500db61af0cb834aab72b0a88dbf689f71bfc