[INFO] cloning repository https://github.com/lucaspoffo/markov_chain
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/lucaspoffo/markov_chain" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucaspoffo%2Fmarkov_chain", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucaspoffo%2Fmarkov_chain'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d67657284eacd67f24653a0209b22304c163396b
[INFO] checking lucaspoffo/markov_chain against try#3e22d1f9053c0fc87629b3c6d5d9567856368e5d for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flucaspoffo%2Fmarkov_chain" "/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/lucaspoffo/markov_chain on toolchain 3e22d1f9053c0fc87629b3c6d5d9567856368e5d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e22d1f9053c0fc87629b3c6d5d9567856368e5d" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/lucaspoffo/markov_chain
[INFO] finished tweaking git repo https://github.com/lucaspoffo/markov_chain
[INFO] tweaked toml for git repo https://github.com/lucaspoffo/markov_chain written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/lucaspoffo/markov_chain already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e22d1f9053c0fc87629b3c6d5d9567856368e5d" "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" "+3e22d1f9053c0fc87629b3c6d5d9567856368e5d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d99815bfd3c8b16aa77ab17bb56d683b670f31236e87b168e58616a97e29cae5
[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" "d99815bfd3c8b16aa77ab17bb56d683b670f31236e87b168e58616a97e29cae5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d99815bfd3c8b16aa77ab17bb56d683b670f31236e87b168e58616a97e29cae5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d99815bfd3c8b16aa77ab17bb56d683b670f31236e87b168e58616a97e29cae5", kill_on_drop: false }`
[INFO] [stdout] d99815bfd3c8b16aa77ab17bb56d683b670f31236e87b168e58616a97e29cae5
[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" "+3e22d1f9053c0fc87629b3c6d5d9567856368e5d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] da51f9bfbd85029cd57cee770c957ba94b277ac68c83d30d9c6f79bee1e489a1
[INFO] running `Command { std: "docker" "start" "-a" "da51f9bfbd85029cd57cee770c957ba94b277ac68c83d30d9c6f79bee1e489a1", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking markov_chain v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:133:7
[INFO] [stdout]     |
[INFO] [stdout] 133 |       write!(f, "\t{:?}:\n", key);
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]    --> src/lib.rs:133:7
[INFO] [stdout]     |
[INFO] [stdout] 133 |       write!(f, "\t{:?}:\n", key);
[INFO] [stdout]     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.65s
[INFO] running `Command { std: "docker" "inspect" "da51f9bfbd85029cd57cee770c957ba94b277ac68c83d30d9c6f79bee1e489a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da51f9bfbd85029cd57cee770c957ba94b277ac68c83d30d9c6f79bee1e489a1", kill_on_drop: false }`
[INFO] [stdout] da51f9bfbd85029cd57cee770c957ba94b277ac68c83d30d9c6f79bee1e489a1