[INFO] cloning repository https://github.com/echochamber/rust_tinkering
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/echochamber/rust_tinkering" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_tinkering", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_tinkering'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 12a61eda676f034377caa5a6878c2f72db0806af
[INFO] testing echochamber/rust_tinkering against try#eafdee2dfae8c2233b74f98b123308be7ccefcc6 for pr-79296
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Frust_tinkering" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/echochamber/rust_tinkering on toolchain eafdee2dfae8c2233b74f98b123308be7ccefcc6
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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-4/source/Cargo.toml
[INFO] crate git repo https://github.com/echochamber/rust_tinkering already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-4/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[INFO] the lockfile is outdated, regenerating it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 `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 096cc740a99a51da6571a5ffc653c24b5a21dd3f5577685843323b633363b4d1
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "096cc740a99a51da6571a5ffc653c24b5a21dd3f5577685843323b633363b4d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "096cc740a99a51da6571a5ffc653c24b5a21dd3f5577685843323b633363b4d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "096cc740a99a51da6571a5ffc653c24b5a21dd3f5577685843323b633363b4d1", kill_on_drop: false }`
[INFO] [stdout] 096cc740a99a51da6571a5ffc653c24b5a21dd3f5577685843323b633363b4d1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 772c831fa873f136c0267498739ad8d543a4c9ebe8fa12478682a65ef5c41677
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "772c831fa873f136c0267498739ad8d543a4c9ebe8fa12478682a65ef5c41677", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.3.1
[INFO] [stderr]    Compiling num-rational v0.3.2
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-complex v0.3.1
[INFO] [stderr]    Compiling num v0.3.1
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]  --> src/reverse_string.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let chars = string_to_reverse.chars();
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 14.45s
[INFO] running `Command { std: "docker" "inspect" "772c831fa873f136c0267498739ad8d543a4c9ebe8fa12478682a65ef5c41677", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "772c831fa873f136c0267498739ad8d543a4c9ebe8fa12478682a65ef5c41677", kill_on_drop: false }`
[INFO] [stdout] 772c831fa873f136c0267498739ad8d543a4c9ebe8fa12478682a65ef5c41677
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1b3fe6cb9b6328135ee9bd1ae8b616f13a55b4c29615cca9e5c9edba9d3d08f6
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "1b3fe6cb9b6328135ee9bd1ae8b616f13a55b4c29615cca9e5c9edba9d3d08f6", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_euler v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]  --> src/reverse_string.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let chars = string_to_reverse.chars();
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]  --> src/reverse_string.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let chars = string_to_reverse.chars();
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.77s
[INFO] running `Command { std: "docker" "inspect" "1b3fe6cb9b6328135ee9bd1ae8b616f13a55b4c29615cca9e5c9edba9d3d08f6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b3fe6cb9b6328135ee9bd1ae8b616f13a55b4c29615cca9e5c9edba9d3d08f6", kill_on_drop: false }`
[INFO] [stdout] 1b3fe6cb9b6328135ee9bd1ae8b616f13a55b4c29615cca9e5c9edba9d3d08f6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+eafdee2dfae8c2233b74f98b123308be7ccefcc6" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 382fbb9b1626a4e7b6d2ca2d5c48d24321b316638848991f250c87835c6d0818
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "382fbb9b1626a4e7b6d2ca2d5c48d24321b316638848991f250c87835c6d0818", kill_on_drop: false }`
[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 0.03s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_euler-d7269676b72a279f
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_euler-9d5c9d3895d5e57f
[INFO] [stdout] running 0 tests
[INFO] [stderr]    Doc-tests rust_euler
[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] [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 `Command { std: "docker" "inspect" "382fbb9b1626a4e7b6d2ca2d5c48d24321b316638848991f250c87835c6d0818", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "382fbb9b1626a4e7b6d2ca2d5c48d24321b316638848991f250c87835c6d0818", kill_on_drop: false }`
[INFO] [stdout] 382fbb9b1626a4e7b6d2ca2d5c48d24321b316638848991f250c87835c6d0818