[INFO] cloning repository https://github.com/gzbakku/letterman
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gzbakku/letterman" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgzbakku%2Fletterman", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgzbakku%2Fletterman'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 106cea8ac105f4b71c830db6cee79dd8912f2388
[INFO] checking gzbakku/letterman against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgzbakku%2Fletterman" "/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/gzbakku/letterman on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/gzbakku/letterman
[INFO] finished tweaking git repo https://github.com/gzbakku/letterman
[INFO] tweaked toml for git repo https://github.com/gzbakku/letterman written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/gzbakku/letterman already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", 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] 0218c1c85ed6d51780121ba3aaca9f692cb7732741fa640f029b5b8c98cdf0f2
[INFO] running `Command { std: "docker" "start" "-a" "0218c1c85ed6d51780121ba3aaca9f692cb7732741fa640f029b5b8c98cdf0f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0218c1c85ed6d51780121ba3aaca9f692cb7732741fa640f029b5b8c98cdf0f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0218c1c85ed6d51780121ba3aaca9f692cb7732741fa640f029b5b8c98cdf0f2", kill_on_drop: false }`
[INFO] [stdout] 0218c1c85ed6d51780121ba3aaca9f692cb7732741fa640f029b5b8c98cdf0f2
[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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b6c8b9dc23606da3702a02d63eff6786eef83bac216fa63d381de2268e30082c
[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" "b6c8b9dc23606da3702a02d63eff6786eef83bac216fa63d381de2268e30082c", kill_on_drop: false }`
[INFO] [stderr]     Checking letterman v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `TcpListener`
[INFO] [stdout]  --> src/main.rs:2:16
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::net::{TcpListener, TcpStream};
[INFO] [stdout]   |                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `actions` is never read
[INFO] [stdout]    --> src/main.rs:105:9
[INFO] [stdout]     |
[INFO] [stdout] 105 |         actions = Vec::new();
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/io.rs:124:9
[INFO] [stdout]     |
[INFO] [stdout] 124 |     let mut letter = line_vec[0].to_string();
[INFO] [stdout]     |         ----^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `log`
[INFO] [stdout]  --> src/common.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub fn log(m: &str){
[INFO] [stdout]   |        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `TcpListener`
[INFO] [stdout]  --> src/main.rs:2:16
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::net::{TcpListener, TcpStream};
[INFO] [stdout]   |                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `actions` is never read
[INFO] [stdout]    --> src/main.rs:105:9
[INFO] [stdout]     |
[INFO] [stdout] 105 |         actions = Vec::new();
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/io.rs:124:9
[INFO] [stdout]     |
[INFO] [stdout] 124 |     let mut letter = line_vec[0].to_string();
[INFO] [stdout]     |         ----^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `log`
[INFO] [stdout]  --> src/common.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub fn log(m: &str){
[INFO] [stdout]   |        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.82s
[INFO] running `Command { std: "docker" "inspect" "b6c8b9dc23606da3702a02d63eff6786eef83bac216fa63d381de2268e30082c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b6c8b9dc23606da3702a02d63eff6786eef83bac216fa63d381de2268e30082c", kill_on_drop: false }`
[INFO] [stdout] b6c8b9dc23606da3702a02d63eff6786eef83bac216fa63d381de2268e30082c