[INFO] cloning repository https://github.com/thesophisticateddev/serial-rust-test
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/thesophisticateddev/serial-rust-test" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthesophisticateddev%2Fserial-rust-test", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthesophisticateddev%2Fserial-rust-test'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f67dcb74b00fcd8de05af81190fdcfa977af8133
[INFO] checking thesophisticateddev/serial-rust-test against master#e1ac0fa95ba15221ee195647cb12464df3164513 for pr-126090
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthesophisticateddev%2Fserial-rust-test" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/thesophisticateddev/serial-rust-test on toolchain e1ac0fa95ba15221ee195647cb12464df3164513
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+e1ac0fa95ba15221ee195647cb12464df3164513" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/thesophisticateddev/serial-rust-test
[INFO] finished tweaking git repo https://github.com/thesophisticateddev/serial-rust-test
[INFO] tweaked toml for git repo https://github.com/thesophisticateddev/serial-rust-test written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/thesophisticateddev/serial-rust-test 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" "+e1ac0fa95ba15221ee195647cb12464df3164513" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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 thesophisticateddev/serial-rust-test against try#09fa13185567a1d9c37905d6a4a2ea56e7f44efc for pr-126090
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fthesophisticateddev%2Fserial-rust-test" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/thesophisticateddev/serial-rust-test on toolchain 09fa13185567a1d9c37905d6a4a2ea56e7f44efc
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+09fa13185567a1d9c37905d6a4a2ea56e7f44efc" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/thesophisticateddev/serial-rust-test
[INFO] finished tweaking git repo https://github.com/thesophisticateddev/serial-rust-test
[INFO] tweaked toml for git repo https://github.com/thesophisticateddev/serial-rust-test written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/thesophisticateddev/serial-rust-test 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" "+09fa13185567a1d9c37905d6a4a2ea56e7f44efc" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+09fa13185567a1d9c37905d6a4a2ea56e7f44efc" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 18c45b1fa77350a28790d255903875a191c0e3a265f4a10fe6369e3ab8d0ff32
[INFO] running `Command { std: "docker" "start" "-a" "18c45b1fa77350a28790d255903875a191c0e3a265f4a10fe6369e3ab8d0ff32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "18c45b1fa77350a28790d255903875a191c0e3a265f4a10fe6369e3ab8d0ff32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "18c45b1fa77350a28790d255903875a191c0e3a265f4a10fe6369e3ab8d0ff32", kill_on_drop: false }`
[INFO] [stdout] 18c45b1fa77350a28790d255903875a191c0e3a265f4a10fe6369e3ab8d0ff32
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:dff56e7819e73ed36160586b3445e93eb0be776c16704aeeded9c3fb668b2384" "/opt/rustwide/cargo-home/bin/cargo" "+09fa13185567a1d9c37905d6a4a2ea56e7f44efc" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bbe299b2ba711f40a5900f6819d2ff9e28c4e17a7e6b434b6d957c608e3e2f75
[INFO] running `Command { std: "docker" "start" "-a" "bbe299b2ba711f40a5900f6819d2ff9e28c4e17a7e6b434b6d957c608e3e2f75", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.146
[INFO] [stderr]    Compiling pkg-config v0.3.27
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking static_assertions v1.1.0
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking bitflags v2.0.2
[INFO] [stderr]    Compiling libudev-sys v0.1.4
[INFO] [stderr]     Checking nix v0.26.2
[INFO] [stderr]     Checking libudev v0.3.0
[INFO] [stderr]     Checking serialport v4.2.1
[INFO] [stderr]     Checking serial-rust-test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     port.flush();
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let _ = port.flush();
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     port.flush();
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let _ = port.flush();
[INFO] [stdout]    |     +++++++
[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` profile [unoptimized + debuginfo] target(s) in 2.54s
[INFO] running `Command { std: "docker" "inspect" "bbe299b2ba711f40a5900f6819d2ff9e28c4e17a7e6b434b6d957c608e3e2f75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bbe299b2ba711f40a5900f6819d2ff9e28c4e17a7e6b434b6d957c608e3e2f75", kill_on_drop: false }`
[INFO] [stdout] bbe299b2ba711f40a5900f6819d2ff9e28c4e17a7e6b434b6d957c608e3e2f75