[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#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fvimcdoe%2Fyield_now_test" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/vimcdoe/yield_now_test on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "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-7-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
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[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6a8a9f2889234ced846e179756fcb62aec4df16f9a78b63a4670f3474bd90c7a
[INFO] running `Command { std: "docker" "start" "-a" "6a8a9f2889234ced846e179756fcb62aec4df16f9a78b63a4670f3474bd90c7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6a8a9f2889234ced846e179756fcb62aec4df16f9a78b63a4670f3474bd90c7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6a8a9f2889234ced846e179756fcb62aec4df16f9a78b63a4670f3474bd90c7a", kill_on_drop: false }`
[INFO] [stdout] 6a8a9f2889234ced846e179756fcb62aec4df16f9a78b63a4670f3474bd90c7a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dd3057bbc1fcab57ef407a8e075bf6d7da6e80128eb40de808747d418e93dcc7
[INFO] running `Command { std: "docker" "start" "-a" "dd3057bbc1fcab57ef407a8e075bf6d7da6e80128eb40de808747d418e93dcc7", kill_on_drop: false }`
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[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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 13.86s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "dd3057bbc1fcab57ef407a8e075bf6d7da6e80128eb40de808747d418e93dcc7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd3057bbc1fcab57ef407a8e075bf6d7da6e80128eb40de808747d418e93dcc7", kill_on_drop: false }`
[INFO] [stdout] dd3057bbc1fcab57ef407a8e075bf6d7da6e80128eb40de808747d418e93dcc7