[INFO] updating cached repository https://github.com/echochamber/rust_tinkering
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/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 master#28742a1146f10a4f09369baad027a464acb7a766 for pr-71274
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_tinkering" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/echochamber/rust_tinkering on toolchain 28742a1146f10a4f09369baad027a464acb7a766
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "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 /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/echochamber/rust_tinkering already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: the lock file /workspace/builds/worker-6/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-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" "+28742a1146f10a4f09369baad027a464acb7a766" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 9793f25d45cbfdc6171a4e3aabd52b6f6b66ef5525b9155afcc6bbee1dbbdd48
[INFO] running `"docker" "start" "-a" "9793f25d45cbfdc6171a4e3aabd52b6f6b66ef5525b9155afcc6bbee1dbbdd48"`
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.40
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling num v0.2.1
[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: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 10.38s
[INFO] running `"docker" "inspect" "9793f25d45cbfdc6171a4e3aabd52b6f6b66ef5525b9155afcc6bbee1dbbdd48"`
[INFO] running `"docker" "rm" "-f" "9793f25d45cbfdc6171a4e3aabd52b6f6b66ef5525b9155afcc6bbee1dbbdd48"`
[INFO] [stdout] 9793f25d45cbfdc6171a4e3aabd52b6f6b66ef5525b9155afcc6bbee1dbbdd48
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-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" "+28742a1146f10a4f09369baad027a464acb7a766" "test" "--frozen" "--no-run"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 45333c2d40fa044c3cd152df0e40dacf3d50a0408d333afd005fe74d81b0586d
[INFO] running `"docker" "start" "-a" "45333c2d40fa044c3cd152df0e40dacf3d50a0408d333afd005fe74d81b0586d"`
[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: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[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: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.01s
[INFO] running `"docker" "inspect" "45333c2d40fa044c3cd152df0e40dacf3d50a0408d333afd005fe74d81b0586d"`
[INFO] running `"docker" "rm" "-f" "45333c2d40fa044c3cd152df0e40dacf3d50a0408d333afd005fe74d81b0586d"`
[INFO] [stdout] 45333c2d40fa044c3cd152df0e40dacf3d50a0408d333afd005fe74d81b0586d
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-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" "+28742a1146f10a4f09369baad027a464acb7a766" "test" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 26074e5471318729fa2b07402d27980ec1398941c27bbf1dd46984afbf948296
[INFO] running `"docker" "start" "-a" "26074e5471318729fa2b07402d27980ec1398941c27bbf1dd46984afbf948296"`
[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: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[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: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.18s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_euler-b8b9f7ab4dfe8823
[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-ecb464cf115e5b52
[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" "26074e5471318729fa2b07402d27980ec1398941c27bbf1dd46984afbf948296"`
[INFO] running `"docker" "rm" "-f" "26074e5471318729fa2b07402d27980ec1398941c27bbf1dd46984afbf948296"`
[INFO] [stdout] 26074e5471318729fa2b07402d27980ec1398941c27bbf1dd46984afbf948296