[INFO] updating cached repository https://github.com/echochamber/rust_tinkering
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 12a61eda676f034377caa5a6878c2f72db0806af
[INFO] testing echochamber/rust_tinkering against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_tinkering" "work/builds/worker-2/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/echochamber/rust_tinkering on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/echochamber/rust_tinkering
[INFO] finished tweaking git repo https://github.com/echochamber/rust_tinkering
[INFO] tweaked toml for git repo https://github.com/echochamber/rust_tinkering written to work/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/echochamber/rust_tinkering already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /big/crater/work/builds/worker-2/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 61e31503f1fd4e66fd6a6490395297051b28909561918dae7b0db3958fa503e0
[INFO] running `"docker" "start" "-a" "61e31503f1fd4e66fd6a6490395297051b28909561918dae7b0db3958fa503e0"`
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling num-bigint v0.2.3
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling num v0.2.0
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/rustwide/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 5.13s
[INFO] running `"docker" "inspect" "61e31503f1fd4e66fd6a6490395297051b28909561918dae7b0db3958fa503e0"`
[INFO] running `"docker" "rm" "-f" "61e31503f1fd4e66fd6a6490395297051b28909561918dae7b0db3958fa503e0"`
[INFO] [stdout] 61e31503f1fd4e66fd6a6490395297051b28909561918dae7b0db3958fa503e0
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] dca423b9d1ca0f5d099e249459560822478cb7f94d9635fff6d26756597ed091
[INFO] running `"docker" "start" "-a" "dca423b9d1ca0f5d099e249459560822478cb7f94d9635fff6d26756597ed091"`
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/rustwide/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 2.04s
[INFO] running `"docker" "inspect" "dca423b9d1ca0f5d099e249459560822478cb7f94d9635fff6d26756597ed091"`
[INFO] running `"docker" "rm" "-f" "dca423b9d1ca0f5d099e249459560822478cb7f94d9635fff6d26756597ed091"`
[INFO] [stdout] dca423b9d1ca0f5d099e249459560822478cb7f94d9635fff6d26756597ed091
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "test" "--frozen"`
[INFO] [stdout] 055abbd9864b10e79749282a38a909c754ad128a4e78c816a46058ef153a7745
[INFO] running `"docker" "start" "-a" "055abbd9864b10e79749282a38a909c754ad128a4e78c816a46058ef153a7745"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.09s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_euler-0d4cefff02308414
[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/rustwide/target/debug/deps/rust_euler-dcd03927093a25c5
[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]    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] running `"docker" "inspect" "055abbd9864b10e79749282a38a909c754ad128a4e78c816a46058ef153a7745"`
[INFO] running `"docker" "rm" "-f" "055abbd9864b10e79749282a38a909c754ad128a4e78c816a46058ef153a7745"`
[INFO] [stdout] 055abbd9864b10e79749282a38a909c754ad128a4e78c816a46058ef153a7745