[INFO] cloning repository https://github.com/ultrasaurus/irc-tokio
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ultrasaurus/irc-tokio" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fultrasaurus%2Firc-tokio", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fultrasaurus%2Firc-tokio'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6fd157604121cd5627a50abc364fe3d2fe96895b
[INFO] checking ultrasaurus/irc-tokio against master#5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f for pr-87248
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fultrasaurus%2Firc-tokio" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ultrasaurus/irc-tokio on toolchain 5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ultrasaurus/irc-tokio
[INFO] finished tweaking git repo https://github.com/ultrasaurus/irc-tokio
[INFO] tweaked toml for git repo https://github.com/ultrasaurus/irc-tokio written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/ultrasaurus/irc-tokio already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 02ac7c348dad39a2ac881361b432a6f09405ae1ac9b31cac889ee9f71b55f236
[INFO] running `Command { std: "docker" "start" "-a" "02ac7c348dad39a2ac881361b432a6f09405ae1ac9b31cac889ee9f71b55f236", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "02ac7c348dad39a2ac881361b432a6f09405ae1ac9b31cac889ee9f71b55f236", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "02ac7c348dad39a2ac881361b432a6f09405ae1ac9b31cac889ee9f71b55f236", kill_on_drop: false }`
[INFO] [stdout] 02ac7c348dad39a2ac881361b432a6f09405ae1ac9b31cac889ee9f71b55f236
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+5a8a44196b3cf099f8c9b0156bd902eaec0b4e5f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f9ff82b435ac8b4f511cb411757507890bf5897db6ecd22cffd55e0b092ca52b
[INFO] running `Command { std: "docker" "start" "-a" "f9ff82b435ac8b4f511cb411757507890bf5897db6ecd22cffd55e0b092ca52b", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]     Checking futures-task v0.3.4
[INFO] [stderr]     Checking futures-io v0.3.4
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling tokio-macros v0.2.4
[INFO] [stderr]     Checking tokio v0.2.11
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]     Checking tokio-util v0.2.0
[INFO] [stderr]     Checking tokio-test v0.2.0
[INFO] [stderr]     Checking futures-executor v0.3.4
[INFO] [stderr]     Checking futures v0.3.4
[INFO] [stderr]     Checking irc-tokio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `irc`
[INFO] [stdout]   --> examples/2b-session-struct.rs:58:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     let irc = Session::connect(addr, &irc_user, &irc_pass).await?;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_irc`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> examples/2b-session-struct.rs:25:14
[INFO] [stdout]    |
[INFO] [stdout] 25 |       panic!(error_str)      // not sure what's a good pattern for returning an error here
[INFO] [stdout]    |              ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]    = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 25 |       panic!("{}", error_str)      // not sure what's a good pattern for returning an error here
[INFO] [stdout]    |              ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 25 |       std::panic::panic_any(error_str)      // not sure what's a good pattern for returning an error here
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 16.32s
[INFO] running `Command { std: "docker" "inspect" "f9ff82b435ac8b4f511cb411757507890bf5897db6ecd22cffd55e0b092ca52b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9ff82b435ac8b4f511cb411757507890bf5897db6ecd22cffd55e0b092ca52b", kill_on_drop: false }`
[INFO] [stdout] f9ff82b435ac8b4f511cb411757507890bf5897db6ecd22cffd55e0b092ca52b