[INFO] cloning repository https://github.com/adragott/Serial_Rust_Learning
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/adragott/Serial_Rust_Learning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadragott%2FSerial_Rust_Learning", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadragott%2FSerial_Rust_Learning'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 793ed8bd526ac92504690f517e2e45b85f92cbc9
[INFO] checking adragott/Serial_Rust_Learning against master#c5af0610196bc39c44e54f1e08bd9149bdc66929 for pr-118120
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadragott%2FSerial_Rust_Learning" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/adragott/Serial_Rust_Learning on toolchain c5af0610196bc39c44e54f1e08bd9149bdc66929
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c5af0610196bc39c44e54f1e08bd9149bdc66929" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-6-tc1/source/.cargo/config
[INFO] started tweaking git repo https://github.com/adragott/Serial_Rust_Learning
[INFO] finished tweaking git repo https://github.com/adragott/Serial_Rust_Learning
[INFO] tweaked toml for git repo https://github.com/adragott/Serial_Rust_Learning written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/adragott/Serial_Rust_Learning 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" "+c5af0610196bc39c44e54f1e08bd9149bdc66929" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking adragott/Serial_Rust_Learning against try#a832c07a2bcc7587230eb0706f83d1d602ae5c2b for pr-118120
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadragott%2FSerial_Rust_Learning" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/adragott/Serial_Rust_Learning on toolchain a832c07a2bcc7587230eb0706f83d1d602ae5c2b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+a832c07a2bcc7587230eb0706f83d1d602ae5c2b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-6-tc2/source/.cargo/config
[INFO] started tweaking git repo https://github.com/adragott/Serial_Rust_Learning
[INFO] finished tweaking git repo https://github.com/adragott/Serial_Rust_Learning
[INFO] tweaked toml for git repo https://github.com/adragott/Serial_Rust_Learning written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/adragott/Serial_Rust_Learning 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" "+a832c07a2bcc7587230eb0706f83d1d602ae5c2b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serial-windows v0.4.0
[INFO] [stderr]   Downloaded serial v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+a832c07a2bcc7587230eb0706f83d1d602ae5c2b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 79d12e606b2bd854f8a77b0907dde8c4044b86e3e7545c00263856741218b57a
[INFO] running `Command { std: "docker" "start" "-a" "79d12e606b2bd854f8a77b0907dde8c4044b86e3e7545c00263856741218b57a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "79d12e606b2bd854f8a77b0907dde8c4044b86e3e7545c00263856741218b57a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "79d12e606b2bd854f8a77b0907dde8c4044b86e3e7545c00263856741218b57a", kill_on_drop: false }`
[INFO] [stdout] 79d12e606b2bd854f8a77b0907dde8c4044b86e3e7545c00263856741218b57a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+a832c07a2bcc7587230eb0706f83d1d602ae5c2b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b525e681e48008f8861b68748b8c7255e0703f4682a20cec81a81859b9beeab9
[INFO] running `Command { std: "docker" "start" "-a" "b525e681e48008f8861b68748b8c7255e0703f4682a20cec81a81859b9beeab9", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]     Checking serial-core v0.4.0
[INFO] [stderr]     Checking ioctl-rs v0.1.6
[INFO] [stderr]     Checking termios v0.2.2
[INFO] [stderr]     Checking serial-unix v0.4.0
[INFO] [stderr]     Checking serial v0.4.0
[INFO] [stderr]     Checking serial_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::str`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::str;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::str`
[INFO] [stdout]  --> src/main.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 | use std::str;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> src/main.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 28 | /     loop
[INFO] [stdout] 29 | |     {
[INFO] [stdout] 30 | |         let mut buf = [0_u8; 256];
[INFO] [stdout] 31 | |         let count = match port.read(&mut buf)
[INFO] [stdout] ...  |
[INFO] [stdout] 43 | |         io::stdout().flush().unwrap();
[INFO] [stdout] 44 | |    }
[INFO] [stdout]    | |____- any code following this expression is unreachable
[INFO] [stdout] 45 |       Ok(())
[INFO] [stdout]    |       ^^^^^^ unreachable expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]   --> src/main.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 28 | /     loop
[INFO] [stdout] 29 | |     {
[INFO] [stdout] 30 | |         let mut buf = [0_u8; 256];
[INFO] [stdout] 31 | |         let count = match port.read(&mut buf)
[INFO] [stdout] ...  |
[INFO] [stdout] 43 | |         io::stdout().flush().unwrap();
[INFO] [stdout] 44 | |    }
[INFO] [stdout]    | |____- any code following this expression is unreachable
[INFO] [stdout] 45 |       Ok(())
[INFO] [stdout]    |       ^^^^^^ unreachable expression
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.28s
[INFO] running `Command { std: "docker" "inspect" "b525e681e48008f8861b68748b8c7255e0703f4682a20cec81a81859b9beeab9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b525e681e48008f8861b68748b8c7255e0703f4682a20cec81a81859b9beeab9", kill_on_drop: false }`
[INFO] [stdout] b525e681e48008f8861b68748b8c7255e0703f4682a20cec81a81859b9beeab9