[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-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/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-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/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#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of robbystk/rust-by-the-book on toolchain try#7fea0229842e79db1159ea58ad9a653b288efee9
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+7fea0229842e79db1159ea58ad9a653b288efee9-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-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/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-57967/sources/try#7fea0229842e79db1159ea58ad9a653b288efee9/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+7fea0229842e79db1159ea58ad9a653b288efee9-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing robbystk/rust-by-the-book against master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54 for pr-57967
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-6/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "build" "--frozen"`
[INFO] [stdout] abe60795b0462fad3447c7754ca5c2fe2886f92b28cbcc373b92e4847488ec01
[INFO] running `"docker" "start" "-a" "abe60795b0462fad3447c7754ca5c2fe2886f92b28cbcc373b92e4847488ec01"`
[INFO] [stderr]    Compiling 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]     Finished dev [unoptimized + debuginfo] target(s) in 0.52s
[INFO] running `"docker" "inspect" "abe60795b0462fad3447c7754ca5c2fe2886f92b28cbcc373b92e4847488ec01"`
[INFO] running `"docker" "rm" "-f" "abe60795b0462fad3447c7754ca5c2fe2886f92b28cbcc373b92e4847488ec01"`
[INFO] [stdout] abe60795b0462fad3447c7754ca5c2fe2886f92b28cbcc373b92e4847488ec01
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-6/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "test" "--frozen" "--no-run"`
[INFO] [stdout] 01a76817e9da7948fd339db272140dc21f90c1f03e6af7a6df6d9d491901f237
[INFO] running `"docker" "start" "-a" "01a76817e9da7948fd339db272140dc21f90c1f03e6af7a6df6d9d491901f237"`
[INFO] [stderr]    Compiling 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]     Finished dev [unoptimized + debuginfo] target(s) in 0.32s
[INFO] running `"docker" "inspect" "01a76817e9da7948fd339db272140dc21f90c1f03e6af7a6df6d9d491901f237"`
[INFO] running `"docker" "rm" "-f" "01a76817e9da7948fd339db272140dc21f90c1f03e6af7a6df6d9d491901f237"`
[INFO] [stdout] 01a76817e9da7948fd339db272140dc21f90c1f03e6af7a6df6d9d491901f237
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-57967/worker-6/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-57967/sources/master#c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54/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" "+c1c3c4e95b69dfeaca5c5db6c622d7f90ad30a54-alt" "test" "--frozen"`
[INFO] [stdout] 7d0c95291ea132420671a2e453b62cfd9be305a18b1b9e2b3c784ff5b7b12f00
[INFO] running `"docker" "start" "-a" "7d0c95291ea132420671a2e453b62cfd9be305a18b1b9e2b3c784ff5b7b12f00"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/errors-1dc504209c42bfdd
[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
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "7d0c95291ea132420671a2e453b62cfd9be305a18b1b9e2b3c784ff5b7b12f00"`
[INFO] running `"docker" "rm" "-f" "7d0c95291ea132420671a2e453b62cfd9be305a18b1b9e2b3c784ff5b7b12f00"`
[INFO] [stdout] 7d0c95291ea132420671a2e453b62cfd9be305a18b1b9e2b3c784ff5b7b12f00