[INFO] cloning repository https://github.com/riojack/rust_look_and_say_kata
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/riojack/rust_look_and_say_kata" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Friojack%2Frust_look_and_say_kata", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Friojack%2Frust_look_and_say_kata'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] acd9aacb63858bdc86db7884e87c00cfc4cc0a3c
[INFO] building riojack/rust_look_and_say_kata against try#d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6 for pr-146237-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Friojack%2Frust_look_and_say_kata" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/riojack/rust_look_and_say_kata
[INFO] finished tweaking git repo https://github.com/riojack/rust_look_and_say_kata
[INFO] tweaked toml for git repo https://github.com/riojack/rust_look_and_say_kata written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/riojack/rust_look_and_say_kata on toolchain d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/riojack/rust_look_and_say_kata already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3edf956a40854cd878c2bfb2b8ce07e85b7d3c1087745aa93af180fb59cb5d6c
[INFO] running `Command { std: "docker" "start" "-a" "3edf956a40854cd878c2bfb2b8ce07e85b7d3c1087745aa93af180fb59cb5d6c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3edf956a40854cd878c2bfb2b8ce07e85b7d3c1087745aa93af180fb59cb5d6c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3edf956a40854cd878c2bfb2b8ce07e85b7d3c1087745aa93af180fb59cb5d6c", kill_on_drop: false }`
[INFO] [stdout] 3edf956a40854cd878c2bfb2b8ce07e85b7d3c1087745aa93af180fb59cb5d6c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9816689dfd102c366071dcf58e4d9c9d4bfad30f8ac70f26b5ab64f530502f99
[INFO] running `Command { std: "docker" "start" "-a" "9816689dfd102c366071dcf58e4d9c9d4bfad30f8ac70f26b5ab64f530502f99", kill_on_drop: false }`
[INFO] [stderr]    Compiling look_and_say_kata v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/algorithm/look_and_say.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_digit_counter = digit_tracker.last_mut().unwrap();
[INFO] [stdout]    |             ----^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.16s
[INFO] running `Command { std: "docker" "inspect" "9816689dfd102c366071dcf58e4d9c9d4bfad30f8ac70f26b5ab64f530502f99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9816689dfd102c366071dcf58e4d9c9d4bfad30f8ac70f26b5ab64f530502f99", kill_on_drop: false }`
[INFO] [stdout] 9816689dfd102c366071dcf58e4d9c9d4bfad30f8ac70f26b5ab64f530502f99
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+d79d87d4c0f7f0d0785ad6e493cf8cf718ed89a6" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1360b15b985df38535568790cffa11e820209a06d6a9b364a5d4ae8ae29e2969
[INFO] running `Command { std: "docker" "start" "-a" "1360b15b985df38535568790cffa11e820209a06d6a9b364a5d4ae8ae29e2969", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.7
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling test-case v0.3.3
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/algorithm/look_and_say.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_digit_counter = digit_tracker.last_mut().unwrap();
[INFO] [stdout]    |             ----^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling look_and_say_kata v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/algorithm/look_and_say.rs:15:13
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_digit_counter = digit_tracker.last_mut().unwrap();
[INFO] [stdout]    |             ----^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 4.80s
[INFO] running `Command { std: "docker" "inspect" "1360b15b985df38535568790cffa11e820209a06d6a9b364a5d4ae8ae29e2969", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1360b15b985df38535568790cffa11e820209a06d6a9b364a5d4ae8ae29e2969", kill_on_drop: false }`
[INFO] [stdout] 1360b15b985df38535568790cffa11e820209a06d6a9b364a5d4ae8ae29e2969