[INFO] cloning repository https://github.com/sczero/mqtt_rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sczero/mqtt_rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsczero%2Fmqtt_rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsczero%2Fmqtt_rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b3aa32f14a19d09dc4f6126675f5f5085577551d
[INFO] testing sczero/mqtt_rs against master#b03b3a7ec92682be2917540b679478d41c95a30c for pr-137122-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsczero%2Fmqtt_rs" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/sczero/mqtt_rs
[INFO] finished tweaking git repo https://github.com/sczero/mqtt_rs
[INFO] tweaked toml for git repo https://github.com/sczero/mqtt_rs written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/sczero/mqtt_rs on toolchain b03b3a7ec92682be2917540b679478d41c95a30c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b03b3a7ec92682be2917540b679478d41c95a30c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/sczero/mqtt_rs 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" "+b03b3a7ec92682be2917540b679478d41c95a30c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded paho-mqtt v0.11.1
[INFO] [stderr]   Downloaded paho-mqtt-sys v0.7.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+b03b3a7ec92682be2917540b679478d41c95a30c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 30cb7d0c5c1df3bed625ee268101f4a55863a054746975dc1b605bdd31bd6d1c
[INFO] running `Command { std: "docker" "start" "-a" "30cb7d0c5c1df3bed625ee268101f4a55863a054746975dc1b605bdd31bd6d1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "30cb7d0c5c1df3bed625ee268101f4a55863a054746975dc1b605bdd31bd6d1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "30cb7d0c5c1df3bed625ee268101f4a55863a054746975dc1b605bdd31bd6d1c", kill_on_drop: false }`
[INFO] [stdout] 30cb7d0c5c1df3bed625ee268101f4a55863a054746975dc1b605bdd31bd6d1c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+b03b3a7ec92682be2917540b679478d41c95a30c" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bb1c841359257aa68bcc55b6fec25d31189d20dd352ca1a05d851027b430ffa6
[INFO] running `Command { std: "docker" "start" "-a" "bb1c841359257aa68bcc55b6fec25d31189d20dd352ca1a05d851027b430ffa6", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.40
[INFO] [stderr]    Compiling unicode-ident v1.0.2
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling quote v1.0.20
[INFO] [stderr]    Compiling syn v1.0.98
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling futures-core v0.3.21
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling futures-task v0.3.21
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]    Compiling pkg-config v0.3.25
[INFO] [stderr]    Compiling slab v0.4.7
[INFO] [stderr]    Compiling pin-project-lite v0.2.9
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling futures-sink v0.3.21
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling lock_api v0.4.7
[INFO] [stderr]    Compiling parking_lot_core v0.9.3
[INFO] [stderr]    Compiling cmake v0.1.45
[INFO] [stderr]    Compiling crossbeam-utils v0.8.10
[INFO] [stderr]    Compiling once_cell v1.13.0
[INFO] [stderr]    Compiling pin-utils v0.1.0
[INFO] [stderr]    Compiling futures-io v0.3.21
[INFO] [stderr]    Compiling cache-padded v1.2.0
[INFO] [stderr]    Compiling smallvec v1.9.0
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling concurrent-queue v1.2.2
[INFO] [stderr]    Compiling tokio v1.20.0
[INFO] [stderr]    Compiling event-listener v2.5.2
[INFO] [stderr]    Compiling crossbeam-channel v0.5.5
[INFO] [stderr]    Compiling mio v0.8.4
[INFO] [stderr]    Compiling async-channel v1.6.1
[INFO] [stderr]    Compiling num_cpus v1.13.1
[INFO] [stderr]    Compiling socket2 v0.4.4
[INFO] [stderr]    Compiling openssl-sys v0.9.75
[INFO] [stderr]    Compiling paho-mqtt-sys v0.7.0
[INFO] [stderr]    Compiling parking_lot v0.12.1
[INFO] [stderr]    Compiling signal-hook-registry v1.4.0
[INFO] [stderr]    Compiling bytes v1.2.0
[INFO] [stderr]    Compiling futures-timer v3.0.2
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling thiserror-impl v1.0.31
[INFO] [stderr]    Compiling tokio-macros v1.8.0
[INFO] [stderr]    Compiling thiserror v1.0.31
[INFO] [stderr]    Compiling futures-executor v0.3.21
[INFO] [stderr]    Compiling futures v0.3.21
[INFO] [stderr]    Compiling paho-mqtt v0.11.1
[INFO] [stderr]    Compiling mqtt_rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::string::FromUtf8Error`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::string::FromUtf8Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/main.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ConnectOptions`, `Message`, `SslOptionsBuilder`, and `SslOptions`
[INFO] [stdout]  --> src/main.rs:7:17
[INFO] [stdout]   |
[INFO] [stdout] 7 | use paho_mqtt::{ConnectOptions, ConnectOptionsBuilder, Message, SslOptions, SslOptionsBuilder};
[INFO] [stdout]   |                 ^^^^^^^^^^^^^^                         ^^^^^^^  ^^^^^^^^^^  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `mqtt_subscribe` is never used
[INFO] [stdout]   --> src/main.rs:49:10
[INFO] [stdout]    |
[INFO] [stdout] 49 | async fn mqtt_subscribe() {}
[INFO] [stdout]    |          ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 0 that must be used
[INFO] [stdout]   --> src/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     tokio::join!(handle1,handle2);
[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]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     tokio::join!(handle1,handle2);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 32.24s
[INFO] running `Command { std: "docker" "inspect" "bb1c841359257aa68bcc55b6fec25d31189d20dd352ca1a05d851027b430ffa6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb1c841359257aa68bcc55b6fec25d31189d20dd352ca1a05d851027b430ffa6", kill_on_drop: false }`
[INFO] [stdout] bb1c841359257aa68bcc55b6fec25d31189d20dd352ca1a05d851027b430ffa6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+b03b3a7ec92682be2917540b679478d41c95a30c" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 486fda8cd5c894c0a400903f0700bc8b6e2488c089ec4f911ad692fddd76a594
[INFO] running `Command { std: "docker" "start" "-a" "486fda8cd5c894c0a400903f0700bc8b6e2488c089ec4f911ad692fddd76a594", kill_on_drop: false }`
[INFO] [stderr]    Compiling mqtt_rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::string::FromUtf8Error`
[INFO] [stdout]  --> src/main.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::string::FromUtf8Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Mutex`
[INFO] [stdout]  --> src/main.rs:3:22
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::sync::{Arc, Mutex};
[INFO] [stdout]   |                      ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `ConnectOptions`, `Message`, `SslOptionsBuilder`, and `SslOptions`
[INFO] [stdout]  --> src/main.rs:7:17
[INFO] [stdout]   |
[INFO] [stdout] 7 | use paho_mqtt::{ConnectOptions, ConnectOptionsBuilder, Message, SslOptions, SslOptionsBuilder};
[INFO] [stdout]   |                 ^^^^^^^^^^^^^^                         ^^^^^^^  ^^^^^^^^^^  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `mqtt_subscribe` is never used
[INFO] [stdout]   --> src/main.rs:49:10
[INFO] [stdout]    |
[INFO] [stdout] 49 | async fn mqtt_subscribe() {}
[INFO] [stdout]    |          ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 0 that must be used
[INFO] [stdout]   --> src/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     tokio::join!(handle1,handle2);
[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]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     tokio::join!(handle1,handle2);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.54s
[INFO] running `Command { std: "docker" "inspect" "486fda8cd5c894c0a400903f0700bc8b6e2488c089ec4f911ad692fddd76a594", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "486fda8cd5c894c0a400903f0700bc8b6e2488c089ec4f911ad692fddd76a594", kill_on_drop: false }`
[INFO] [stdout] 486fda8cd5c894c0a400903f0700bc8b6e2488c089ec4f911ad692fddd76a594
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+b03b3a7ec92682be2917540b679478d41c95a30c" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 328e6ee02eeff01bf64a97ce8f5756d21c4c9b51e5219d7ce94306792ae19a3d
[INFO] running `Command { std: "docker" "start" "-a" "328e6ee02eeff01bf64a97ce8f5756d21c4c9b51e5219d7ce94306792ae19a3d", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::string::FromUtf8Error`
[INFO] [stderr]  --> src/main.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::string::FromUtf8Error;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Mutex`
[INFO] [stderr]  --> src/main.rs:3:22
[INFO] [stderr]   |
[INFO] [stderr] 3 | use std::sync::{Arc, Mutex};
[INFO] [stderr]   |                      ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `ConnectOptions`, `Message`, `SslOptionsBuilder`, and `SslOptions`
[INFO] [stderr]  --> src/main.rs:7:17
[INFO] [stderr]   |
[INFO] [stderr] 7 | use paho_mqtt::{ConnectOptions, ConnectOptionsBuilder, Message, SslOptions, SslOptionsBuilder};
[INFO] [stderr]   |                 ^^^^^^^^^^^^^^                         ^^^^^^^  ^^^^^^^^^^  ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `mqtt_subscribe` is never used
[INFO] [stderr]   --> src/main.rs:49:10
[INFO] [stderr]    |
[INFO] [stderr] 49 | async fn mqtt_subscribe() {}
[INFO] [stderr]    |          ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` in tuple element 0 that must be used
[INFO] [stderr]   --> src/main.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 38 |     tokio::join!(handle1,handle2);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stderr]   --> src/main.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 38 |     tokio::join!(handle1,handle2);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `$crate::join` which comes from the expansion of the macro `tokio::join` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: `mqtt_rs` (bin "mqtt_rs" test) generated 6 warnings (run `cargo fix --bin "mqtt_rs" --tests` to apply 3 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.10s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/mqtt_rs-a7469a5b6ff300a1)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "328e6ee02eeff01bf64a97ce8f5756d21c4c9b51e5219d7ce94306792ae19a3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "328e6ee02eeff01bf64a97ce8f5756d21c4c9b51e5219d7ce94306792ae19a3d", kill_on_drop: false }`
[INFO] [stdout] 328e6ee02eeff01bf64a97ce8f5756d21c4c9b51e5219d7ce94306792ae19a3d