[INFO] fetching crate serial-rs 0.2.1...
[INFO] checking serial-rs-0.2.1 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate serial-rs 0.2.1 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate serial-rs 0.2.1 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serial-rs 0.2.1
[INFO] finished tweaking crates.io crate serial-rs 0.2.1
[INFO] tweaked toml for crates.io crate serial-rs 0.2.1 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate crates.io crate serial-rs 0.2.1 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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 33aceb19b881ed331544dbee35058fe1ac82f0a2fc6cab257c7df34c62058b76
[INFO] running `Command { std: "docker" "start" "-a" "33aceb19b881ed331544dbee35058fe1ac82f0a2fc6cab257c7df34c62058b76", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "33aceb19b881ed331544dbee35058fe1ac82f0a2fc6cab257c7df34c62058b76", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "33aceb19b881ed331544dbee35058fe1ac82f0a2fc6cab257c7df34c62058b76", kill_on_drop: false }`
[INFO] [stdout] 33aceb19b881ed331544dbee35058fe1ac82f0a2fc6cab257c7df34c62058b76
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f9f540faeb40f2224d8e197916705665a48983eb80f55b949c55a2d75c83546e
[INFO] running `Command { std: "docker" "start" "-a" "f9f540faeb40f2224d8e197916705665a48983eb80f55b949c55a2d75c83546e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.119
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking nix v0.23.1
[INFO] [stderr]     Checking serial-rs v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Result`
[INFO] [stdout]  --> src/posix/ioctl.rs:4:99
[INFO] [stdout]   |
[INFO] [stdout] 4 | use nix::{ioctl_none_bad, libc, ioctl_read_bad, ioctl_write_ptr_bad, ioctl_read, ioctl_write_ptr, Result};
[INFO] [stdout]   |                                                                                                   ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Result`
[INFO] [stdout]  --> src/posix/ioctl.rs:4:99
[INFO] [stdout]   |
[INFO] [stdout] 4 | use nix::{ioctl_none_bad, libc, ioctl_read_bad, ioctl_write_ptr_bad, ioctl_read, ioctl_write_ptr, Result};
[INFO] [stdout]   |                                                                                                   ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/posix/port_lister.rs:27:13
[INFO] [stdout]    |
[INFO] [stdout] 27 |         let mut pat: Vec<PathBuf> = get_paths("/dev/ttyS*").into_iter()
[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: unused `Result` that must be used
[INFO] [stdout]   --> src/posix/port_lister.rs:52:21
[INFO] [stdout]    |
[INFO] [stdout] 52 |                     f.read_to_string(&mut s);
[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] 52 |                     let _ = f.read_to_string(&mut s);
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/posix/port_lister.rs:27:13
[INFO] [stdout]    |
[INFO] [stdout] 27 |         let mut pat: Vec<PathBuf> = get_paths("/dev/ttyS*").into_iter()
[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: unused `Result` that must be used
[INFO] [stdout]   --> src/posix/port_lister.rs:52:21
[INFO] [stdout]    |
[INFO] [stdout] 52 |                     f.read_to_string(&mut s);
[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] 52 |                     let _ = f.read_to_string(&mut s);
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `BufWriter`, `Read`
[INFO] [stdout]  --> examples/port_list.rs:1:15
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io::{Read, BufReader, BufRead, Write, BufWriter};
[INFO] [stdout]   |               ^^^^                             ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.51s
[INFO] running `Command { std: "docker" "inspect" "f9f540faeb40f2224d8e197916705665a48983eb80f55b949c55a2d75c83546e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9f540faeb40f2224d8e197916705665a48983eb80f55b949c55a2d75c83546e", kill_on_drop: false }`
[INFO] [stdout] f9f540faeb40f2224d8e197916705665a48983eb80f55b949c55a2d75c83546e