[INFO] updating cached repository echochamber/rust_tinkering
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/echochamber/rust_tinkering
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/echochamber/rust_tinkering" "work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/echochamber/rust_tinkering" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/echochamber/rust_tinkering"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/echochamber/rust_tinkering'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 12a61eda676f034377caa5a6878c2f72db0806af
[INFO] sha for GitHub repo echochamber/rust_tinkering: 12a61eda676f034377caa5a6878c2f72db0806af
[INFO] validating manifest of echochamber/rust_tinkering on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of echochamber/rust_tinkering on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing echochamber/rust_tinkering
[INFO] finished frobbing echochamber/rust_tinkering
[INFO] frobbed toml for echochamber/rust_tinkering written to work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering/Cargo.toml
[INFO] started frobbing echochamber/rust_tinkering
[INFO] finished frobbing echochamber/rust_tinkering
[INFO] frobbed toml for echochamber/rust_tinkering written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/echochamber/rust_tinkering/Cargo.toml
[INFO] crate echochamber/rust_tinkering already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing echochamber/rust_tinkering against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering:/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=warn" "-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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] 764383d226bea209ba0c8b344f2933b7f5ae1910bd0de2d1a96054988551ccf0
[INFO] running `"docker" "start" "-a" "764383d226bea209ba0c8b344f2933b7f5ae1910bd0de2d1a96054988551ccf0"`
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `chars`
[INFO] [stderr]  --> src/reverse_string.rs:6:9
[INFO] [stderr]   |
[INFO] [stderr] 6 |     let chars = string_to_reverse.chars();
[INFO] [stderr]   |         ^^^^^ help: consider prefixing with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.55s
[INFO] running `"docker" "inspect" "764383d226bea209ba0c8b344f2933b7f5ae1910bd0de2d1a96054988551ccf0"`
[INFO] running `"docker" "rm" "-f" "764383d226bea209ba0c8b344f2933b7f5ae1910bd0de2d1a96054988551ccf0"`
[INFO] [stdout] 764383d226bea209ba0c8b344f2933b7f5ae1910bd0de2d1a96054988551ccf0
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering:/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=warn" "-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" "+1.36.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] eaa226fff4cb2971c726dbeb3a11250c5b5c196a5f55226ecf058de563f64fc5
[INFO] running `"docker" "start" "-a" "eaa226fff4cb2971c726dbeb3a11250c5b5c196a5f55226ecf058de563f64fc5"`
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `chars`
[INFO] [stderr]  --> src/reverse_string.rs:6:9
[INFO] [stderr]   |
[INFO] [stderr] 6 |     let chars = string_to_reverse.chars();
[INFO] [stderr]   |         ^^^^^ help: consider prefixing with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.04s
[INFO] running `"docker" "inspect" "eaa226fff4cb2971c726dbeb3a11250c5b5c196a5f55226ecf058de563f64fc5"`
[INFO] running `"docker" "rm" "-f" "eaa226fff4cb2971c726dbeb3a11250c5b5c196a5f55226ecf058de563f64fc5"`
[INFO] [stdout] eaa226fff4cb2971c726dbeb3a11250c5b5c196a5f55226ecf058de563f64fc5
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/gh/echochamber/rust_tinkering:/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=warn" "-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" "+1.36.0" "test" "--frozen"`
[INFO] [stdout] 00e39505a800a0e25ab5a64d74ea08127d56e6e1a0976f2379b5abdc457af2ac
[INFO] running `"docker" "start" "-a" "00e39505a800a0e25ab5a64d74ea08127d56e6e1a0976f2379b5abdc457af2ac"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/rust_euler-7f45407511a43b41
[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] [stderr]      Running /opt/crater/target/debug/deps/rust_euler-7efff4ec240cca9c
[INFO] [stderr]    Doc-tests rust_euler
[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] [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" "00e39505a800a0e25ab5a64d74ea08127d56e6e1a0976f2379b5abdc457af2ac"`
[INFO] running `"docker" "rm" "-f" "00e39505a800a0e25ab5a64d74ea08127d56e6e1a0976f2379b5abdc457af2ac"`
[INFO] [stdout] 00e39505a800a0e25ab5a64d74ea08127d56e6e1a0976f2379b5abdc457af2ac