[INFO] cloning repository https://github.com/AbsoluteVirtueXI/thread-channel
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AbsoluteVirtueXI/thread-channel" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAbsoluteVirtueXI%2Fthread-channel", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAbsoluteVirtueXI%2Fthread-channel'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 786f8894bc76f5cc55a8dede2d4cabdcaa6ab642
[INFO] checking AbsoluteVirtueXI/thread-channel against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAbsoluteVirtueXI%2Fthread-channel" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/AbsoluteVirtueXI/thread-channel 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/AbsoluteVirtueXI/thread-channel
[INFO] finished tweaking git repo https://github.com/AbsoluteVirtueXI/thread-channel
[INFO] tweaked toml for git repo https://github.com/AbsoluteVirtueXI/thread-channel written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/AbsoluteVirtueXI/thread-channel 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 quote v1.0.4
[INFO] [stderr]   Downloaded futures-sink v0.3.4
[INFO] [stderr]   Downloaded miow v0.3.3
[INFO] [stderr]   Downloaded pin-project-lite v0.1.4
[INFO] [stderr]   Downloaded proc-macro2 v1.0.12
[INFO] [stderr]   Downloaded futures-executor v0.3.4
[INFO] [stderr]   Downloaded futures-channel v0.3.4
[INFO] [stderr]   Downloaded futures-util v0.3.4
[INFO] [stderr]   Downloaded libc v0.2.69
[INFO] [stderr]   Downloaded tokio v0.2.20
[INFO] [stderr]   Downloaded syn v1.0.18
[INFO] [stderr]   Downloaded futures-io v0.3.4
[INFO] [stderr]   Downloaded futures-macro v0.3.4
[INFO] [stderr]   Downloaded futures-task v0.3.4
[INFO] [stderr]   Downloaded futures v0.3.4
[INFO] [stderr]   Downloaded futures-core v0.3.4
[INFO] [stderr]   Downloaded arc-swap v0.4.6
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 88b1c1eeaa3a6fa34f16aec06fa70d46a4ca4c6356157d3442cf6f9d6a312db0
[INFO] running `Command { std: "docker" "start" "-a" "88b1c1eeaa3a6fa34f16aec06fa70d46a4ca4c6356157d3442cf6f9d6a312db0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "88b1c1eeaa3a6fa34f16aec06fa70d46a4ca4c6356157d3442cf6f9d6a312db0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "88b1c1eeaa3a6fa34f16aec06fa70d46a4ca4c6356157d3442cf6f9d6a312db0", kill_on_drop: false }`
[INFO] [stdout] 88b1c1eeaa3a6fa34f16aec06fa70d46a4ca4c6356157d3442cf6f9d6a312db0
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d2df2155029d57c73fde9ccd8d680fc5067acf99ec1536b0433eeee2aba50a4
[INFO] running `Command { std: "docker" "start" "-a" "8d2df2155029d57c73fde9ccd8d680fc5067acf99ec1536b0433eeee2aba50a4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.12
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]     Checking futures-io v0.3.4
[INFO] [stderr]     Checking futures-task v0.3.4
[INFO] [stderr]     Checking arc-swap v0.4.6
[INFO] [stderr]     Checking bytes v0.5.4
[INFO] [stderr]     Checking pin-project-lite v0.1.4
[INFO] [stderr]     Checking fnv v1.0.6
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]    Compiling quote v1.0.4
[INFO] [stderr]     Checking net2 v0.2.34
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking mio v0.6.22
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]     Checking tokio v0.2.20
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]     Checking futures-executor v0.3.4
[INFO] [stderr]     Checking futures v0.3.4
[INFO] [stderr]     Checking trash-tokio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/main.rs:7:18
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let (mut tx, mut rx) = mpsc::channel(100);
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/main.rs:7:18
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let (mut tx, mut rx) = mpsc::channel(100);
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.90s
[INFO] running `Command { std: "docker" "inspect" "8d2df2155029d57c73fde9ccd8d680fc5067acf99ec1536b0433eeee2aba50a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d2df2155029d57c73fde9ccd8d680fc5067acf99ec1536b0433eeee2aba50a4", kill_on_drop: false }`
[INFO] [stdout] 8d2df2155029d57c73fde9ccd8d680fc5067acf99ec1536b0433eeee2aba50a4