[INFO] cloning repository https://github.com/vimcdoe/yield_now_test
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/vimcdoe/yield_now_test" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvimcdoe%2Fyield_now_test", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvimcdoe%2Fyield_now_test'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ec5c9da05443eae08f747d0704a51cf4de9d49aa
[INFO] checking vimcdoe/yield_now_test against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvimcdoe%2Fyield_now_test" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/vimcdoe/yield_now_test 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/vimcdoe/yield_now_test
[INFO] removed 0 missing examples
[INFO] finished tweaking git repo https://github.com/vimcdoe/yield_now_test
[INFO] tweaked toml for git repo https://github.com/vimcdoe/yield_now_test written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/vimcdoe/yield_now_test 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded async-global-executor v1.4.2
[INFO] [stderr]   Downloaded smol v1.2.4
[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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a7bd60abda2188f5f9cc6393118d1269c6fdc017631b1671b5bad4dd80eaf1ce
[INFO] running `Command { std: "docker" "start" "-a" "a7bd60abda2188f5f9cc6393118d1269c6fdc017631b1671b5bad4dd80eaf1ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a7bd60abda2188f5f9cc6393118d1269c6fdc017631b1671b5bad4dd80eaf1ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7bd60abda2188f5f9cc6393118d1269c6fdc017631b1671b5bad4dd80eaf1ce", kill_on_drop: false }`
[INFO] [stdout] a7bd60abda2188f5f9cc6393118d1269c6fdc017631b1671b5bad4dd80eaf1ce
[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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fbefa9012aa7c9fe92b89988697cc64dd3beb0d44b9cb1ce29b92c6a42c6df65
[INFO] running `Command { std: "docker" "start" "-a" "fbefa9012aa7c9fe92b89988697cc64dd3beb0d44b9cb1ce29b92c6a42c6df65", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]     Checking futures-core v0.3.6
[INFO] [stderr]     Checking pin-project-lite v0.1.11
[INFO] [stderr]     Checking cache-padded v1.1.1
[INFO] [stderr]     Checking futures-io v0.3.6
[INFO] [stderr]     Checking fastrand v1.4.0
[INFO] [stderr]     Checking waker-fn v1.1.0
[INFO] [stderr]     Checking parking v2.0.0
[INFO] [stderr]     Checking event-listener v2.5.1
[INFO] [stderr]     Checking once_cell v1.4.1
[INFO] [stderr]     Checking async-task v4.0.3
[INFO] [stderr]     Checking vec-arena v1.0.0
[INFO] [stderr]    Compiling syn v1.0.46
[INFO] [stderr]     Checking nb-connect v1.0.2
[INFO] [stderr]     Checking arc-swap v0.4.7
[INFO] [stderr]     Checking atomic-waker v1.0.0
[INFO] [stderr]     Checking instant v0.1.7
[INFO] [stderr]     Checking smallvec v1.4.2
[INFO] [stderr]     Checking concurrent-queue v1.2.2
[INFO] [stderr]     Checking lock_api v0.4.1
[INFO] [stderr]     Checking async-lock v2.3.0
[INFO] [stderr]     Checking async-mutex v1.4.0
[INFO] [stderr]     Checking bytes v0.6.0
[INFO] [stderr]     Checking async-channel v1.5.1
[INFO] [stderr]     Checking parking_lot_core v0.8.0
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[INFO] [stderr]     Checking parking_lot v0.11.0
[INFO] [stderr]     Checking signal-hook v0.1.16
[INFO] [stderr]     Checking futures-lite v1.11.2
[INFO] [stderr]     Checking polling v2.0.2
[INFO] [stderr]     Checking mio v0.7.4
[INFO] [stderr]     Checking kv-log-macro v1.0.7
[INFO] [stderr]     Checking async-io v1.1.10
[INFO] [stderr]     Checking blocking v1.0.2
[INFO] [stderr]     Checking async-executor v1.3.0
[INFO] [stderr]     Checking async-fs v1.5.0
[INFO] [stderr]     Checking async-process v1.0.1
[INFO] [stderr]     Checking async-net v1.5.0
[INFO] [stderr]     Checking async-global-executor v1.4.2
[INFO] [stderr]     Checking smol v1.2.4
[INFO] [stderr]    Compiling async-attributes v1.1.1
[INFO] [stderr]    Compiling tokio-macros v0.3.0
[INFO] [stderr]     Checking async-std v1.6.5
[INFO] [stderr]     Checking tokio v0.3.1
[INFO] [stderr]     Checking rtest v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused output of future returned by `tokio::task::yield_now` that must be used
[INFO] [stdout]  --> examples/tokio.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         tokio::task::yield_now().await;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: yield_now does nothing unless polled/`await`-ed
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 7 |         let _ = tokio::task::yield_now().await;
[INFO] [stdout]   |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.35s
[INFO] running `Command { std: "docker" "inspect" "fbefa9012aa7c9fe92b89988697cc64dd3beb0d44b9cb1ce29b92c6a42c6df65", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fbefa9012aa7c9fe92b89988697cc64dd3beb0d44b9cb1ce29b92c6a42c6df65", kill_on_drop: false }`
[INFO] [stdout] fbefa9012aa7c9fe92b89988697cc64dd3beb0d44b9cb1ce29b92c6a42c6df65