[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-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/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-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/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#6ecad338381cc3b8d56e2df22e5971a598eddd6c
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of robbystk/rust-by-the-book on toolchain try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f789154f114767b2d0cb9c5b6c592cb3a635e6f-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-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/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-57501/sources/try#5f789154f114767b2d0cb9c5b6c592cb3a635e6f/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" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+5f789154f114767b2d0cb9c5b6c592cb3a635e6f-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking robbystk/rust-by-the-book against master#6ecad338381cc3b8d56e2df22e5971a598eddd6c for pr-57501
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57501/worker-7/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57501/sources/master#6ecad338381cc3b8d56e2df22e5971a598eddd6c/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" "+6ecad338381cc3b8d56e2df22e5971a598eddd6c-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] bbca387b539dd5e18a9875bfd3a6dc7f87fd8abe0688c5e7f0bcf8e0146fb2a0
[INFO] running `"docker" "start" "-a" "bbca387b539dd5e18a9875bfd3a6dc7f87fd8abe0688c5e7f0bcf8e0146fb2a0"`
[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 using `_f` instead
[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 using `_f` instead
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.36s
[INFO] running `"docker" "inspect" "bbca387b539dd5e18a9875bfd3a6dc7f87fd8abe0688c5e7f0bcf8e0146fb2a0"`
[INFO] running `"docker" "rm" "-f" "bbca387b539dd5e18a9875bfd3a6dc7f87fd8abe0688c5e7f0bcf8e0146fb2a0"`
[INFO] [stdout] bbca387b539dd5e18a9875bfd3a6dc7f87fd8abe0688c5e7f0bcf8e0146fb2a0