[INFO] cloning repository https://github.com/andygrove/rust-qik
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/andygrove/rust-qik" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandygrove%2Frust-qik", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandygrove%2Frust-qik'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 16fe79a19d5d613d427ed784dcb7906ff76438ca
[INFO] checking andygrove/rust-qik against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandygrove%2Frust-qik" "/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/andygrove/rust-qik on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/andygrove/rust-qik
[INFO] finished tweaking git repo https://github.com/andygrove/rust-qik
[INFO] tweaked toml for git repo https://github.com/andygrove/rust-qik written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/andygrove/rust-qik 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serial v0.3.4
[INFO] [stderr]   Downloaded thread_local v0.2.6
[INFO] [stderr]   Downloaded libc v0.2.15
[INFO] [stderr]   Downloaded nix v0.6.0
[INFO] [stderr]   Downloaded regex-syntax v0.3.5
[INFO] [stderr]   Downloaded regex v0.1.76
[INFO] [stderr]   Downloaded sysfs_gpio v0.4.4
[INFO] [stderr]   Downloaded ioctl-rs v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1bba3a49ce83d9688df7bfca1220805b47d014014845a5d92a0a706bde483ad9
[INFO] running `Command { std: "docker" "start" "-a" "1bba3a49ce83d9688df7bfca1220805b47d014014845a5d92a0a706bde483ad9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1bba3a49ce83d9688df7bfca1220805b47d014014845a5d92a0a706bde483ad9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1bba3a49ce83d9688df7bfca1220805b47d014014845a5d92a0a706bde483ad9", kill_on_drop: false }`
[INFO] [stdout] 1bba3a49ce83d9688df7bfca1220805b47d014014845a5d92a0a706bde483ad9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1b0d5fc923d7a90eae018004bac75df89a136a49dbd6e2e6815f6847c65f67b9
[INFO] running `Command { std: "docker" "start" "-a" "1b0d5fc923d7a90eae018004bac75df89a136a49dbd6e2e6815f6847c65f67b9", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.15
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]    Compiling semver v0.1.20
[INFO] [stderr]     Checking winapi v0.2.8
[INFO] [stderr]     Checking regex-syntax v0.3.5
[INFO] [stderr]     Checking utf8-ranges v0.1.3
[INFO] [stderr]     Checking cfg-if v0.1.0
[INFO] [stderr]     Checking bitflags v0.4.0
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]    Compiling rustc_version v0.1.7
[INFO] [stderr]     Checking memchr v0.1.11
[INFO] [stderr]     Checking ioctl-rs v0.1.5
[INFO] [stderr]     Checking termios v0.2.2
[INFO] [stderr]     Checking aho-corasick v0.5.3
[INFO] [stderr]     Checking serial v0.3.4
[INFO] [stderr]    Compiling nix v0.6.0
[INFO] [stderr]     Checking thread-id v2.0.0
[INFO] [stderr]     Checking thread_local v0.2.6
[INFO] [stderr]     Checking regex v0.1.76
[INFO] [stderr]     Checking sysfs_gpio v0.4.4
[INFO] [stderr]     Checking qik v1.2.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `From` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::convert::From;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:124:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `From` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:153:9
[INFO] [stdout]     |
[INFO] [stdout] 153 |         try!(port.reconfigure(&|settings| {
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:162:9
[INFO] [stdout]     |
[INFO] [stdout] 162 |         try!(port.set_timeout(Duration::from_millis(5000)));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:151:24
[INFO] [stdout]     |
[INFO] [stdout] 151 |         let mut port = try!(serial::open(&device).map_err(QikError::SerialErr));
[INFO] [stdout]     |                        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:154:13
[INFO] [stdout]     |
[INFO] [stdout] 154 |             try!(settings.set_baud_rate(serial::Baud9600));
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:174:9
[INFO] [stdout]     |
[INFO] [stdout] 174 |         try!(self.write_byte(0xAA));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:169:13
[INFO] [stdout]     |
[INFO] [stdout] 169 |             try!(self.reset());
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:171:13
[INFO] [stdout]     |
[INFO] [stdout] 171 |             try!(self.reset_pin.with_exported(|| self.reset()));
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |         try!(self.reset_pin.set_value(0));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:180:9
[INFO] [stdout]     |
[INFO] [stdout] 180 |         try!(self.reset_pin.set_direction(Direction::Out));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:182:9
[INFO] [stdout]     |
[INFO] [stdout] 182 |         try!(self.reset_pin.set_direction(Direction::In));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:198:9
[INFO] [stdout]     |
[INFO] [stdout] 198 |         try!(self.write(&cmd));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |         try!(self.write(&cmd));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |         try!(self.write_byte(get_cmd_byte(match m {
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:281:9
[INFO] [stdout]     |
[INFO] [stdout] 281 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:287:17
[INFO] [stdout]     |
[INFO] [stdout] 287 |         let c = try!(self.get_current(m));
[INFO] [stdout]     |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:294:9
[INFO] [stdout]     |
[INFO] [stdout] 294 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:300:9
[INFO] [stdout]     |
[INFO] [stdout] 300 |         try!(self.port.write_all(buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:306:19
[INFO] [stdout]     |
[INFO] [stdout] 306 |         let buf = try!(self.read(1));
[INFO] [stdout]     |                   ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:313:9
[INFO] [stdout]     |
[INFO] [stdout] 313 |         try!(self.port.read_exact(buf.as_mut()));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `From` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::convert::From;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:124:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `From` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:153:9
[INFO] [stdout]     |
[INFO] [stdout] 153 |         try!(port.reconfigure(&|settings| {
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:162:9
[INFO] [stdout]     |
[INFO] [stdout] 162 |         try!(port.set_timeout(Duration::from_millis(5000)));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:151:24
[INFO] [stdout]     |
[INFO] [stdout] 151 |         let mut port = try!(serial::open(&device).map_err(QikError::SerialErr));
[INFO] [stdout]     |                        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:154:13
[INFO] [stdout]     |
[INFO] [stdout] 154 |             try!(settings.set_baud_rate(serial::Baud9600));
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:174:9
[INFO] [stdout]     |
[INFO] [stdout] 174 |         try!(self.write_byte(0xAA));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:169:13
[INFO] [stdout]     |
[INFO] [stdout] 169 |             try!(self.reset());
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:171:13
[INFO] [stdout]     |
[INFO] [stdout] 171 |             try!(self.reset_pin.with_exported(|| self.reset()));
[INFO] [stdout]     |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:179:9
[INFO] [stdout]     |
[INFO] [stdout] 179 |         try!(self.reset_pin.set_value(0));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:180:9
[INFO] [stdout]     |
[INFO] [stdout] 180 |         try!(self.reset_pin.set_direction(Direction::Out));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:182:9
[INFO] [stdout]     |
[INFO] [stdout] 182 |         try!(self.reset_pin.set_direction(Direction::In));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:198:9
[INFO] [stdout]     |
[INFO] [stdout] 198 |         try!(self.write(&cmd));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:210:9
[INFO] [stdout]     |
[INFO] [stdout] 210 |         try!(self.write(&cmd));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:268:9
[INFO] [stdout]     |
[INFO] [stdout] 268 |         try!(self.write_byte(get_cmd_byte(match m {
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:281:9
[INFO] [stdout]     |
[INFO] [stdout] 281 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:287:17
[INFO] [stdout]     |
[INFO] [stdout] 287 |         let c = try!(self.get_current(m));
[INFO] [stdout]     |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:294:9
[INFO] [stdout]     |
[INFO] [stdout] 294 |         try!(self.write(&buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:300:9
[INFO] [stdout]     |
[INFO] [stdout] 300 |         try!(self.port.write_all(buf));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:306:19
[INFO] [stdout]     |
[INFO] [stdout] 306 |         let buf = try!(self.read(1));
[INFO] [stdout]     |                   ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:313:9
[INFO] [stdout]     |
[INFO] [stdout] 313 |         try!(self.port.read_exact(buf.as_mut()));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 22 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 22 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.90s
[INFO] running `Command { std: "docker" "inspect" "1b0d5fc923d7a90eae018004bac75df89a136a49dbd6e2e6815f6847c65f67b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b0d5fc923d7a90eae018004bac75df89a136a49dbd6e2e6815f6847c65f67b9", kill_on_drop: false }`
[INFO] [stdout] 1b0d5fc923d7a90eae018004bac75df89a136a49dbd6e2e6815f6847c65f67b9