[INFO] cloning repository https://github.com/ranafge/rust_async_await
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ranafge/rust_async_await" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Franafge%2Frust_async_await", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Franafge%2Frust_async_await'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b00438e21ceae2c67a41166ae3dac8dbdc8751c4
[INFO] checking ranafge/rust_async_await against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Franafge%2Frust_async_await" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ranafge/rust_async_await 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/ranafge/rust_async_await
[INFO] finished tweaking git repo https://github.com/ranafge/rust_async_await
[INFO] tweaked toml for git repo https://github.com/ranafge/rust_async_await written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/ranafge/rust_async_await 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 59aa07acc5172ba535633cb91a855d5e217e488f57b40b71aa590c348ba51dc6
[INFO] running `Command { std: "docker" "start" "-a" "59aa07acc5172ba535633cb91a855d5e217e488f57b40b71aa590c348ba51dc6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "59aa07acc5172ba535633cb91a855d5e217e488f57b40b71aa590c348ba51dc6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59aa07acc5172ba535633cb91a855d5e217e488f57b40b71aa590c348ba51dc6", kill_on_drop: false }`
[INFO] [stdout] 59aa07acc5172ba535633cb91a855d5e217e488f57b40b71aa590c348ba51dc6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] b66932a279d90ef257d72ab17644c74cceb5503c58f234d17a92baa9bdadb54c
[INFO] running `Command { std: "docker" "start" "-a" "b66932a279d90ef257d72ab17644c74cceb5503c58f234d17a92baa9bdadb54c", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.70
[INFO] [stderr]    Compiling libc v0.2.151
[INFO] [stderr]    Compiling futures-core v0.3.29
[INFO] [stderr]    Compiling futures-channel v0.3.29
[INFO] [stderr]     Checking futures-sink v0.3.29
[INFO] [stderr]    Compiling futures-util v0.3.29
[INFO] [stderr]     Checking async_await v0.1.0 (/opt/rustwide/workdir/async_await)
[INFO] [stderr]     Checking rust_futures_for_string v0.1.0 (/opt/rustwide/workdir/rust_futures_for_string)
[INFO] [stdout] warning: unused variable: `cx`
[INFO] [stdout]  --> rust_futures_for_string/src/lib.rs:8:45
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn poll(self: std::pin::Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> std::task::Poll<Self::Output> {
[INFO] [stdout]   |                                             ^^ help: if this is intentional, prefix it with an underscore: `_cx`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking parking_lot_core v0.9.9
[INFO] [stderr]     Checking signal-hook-registry v1.4.1
[INFO] [stderr]     Checking socket2 v0.5.5
[INFO] [stderr]     Checking mio v0.8.10
[INFO] [stderr]     Checking num_cpus v1.16.0
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]    Compiling syn v2.0.40
[INFO] [stderr]    Compiling futures-macro v0.3.29
[INFO] [stderr]    Compiling tokio-macros v2.2.0
[INFO] [stderr]     Checking tokio v1.35.0
[INFO] [stderr]     Checking futures-executor v0.3.29
[INFO] [stderr]     Checking futures v0.3.29
[INFO] [stderr]     Checking firstchapter_asyncawait v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 15.81s
[INFO] running `Command { std: "docker" "inspect" "b66932a279d90ef257d72ab17644c74cceb5503c58f234d17a92baa9bdadb54c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b66932a279d90ef257d72ab17644c74cceb5503c58f234d17a92baa9bdadb54c", kill_on_drop: false }`
[INFO] [stdout] b66932a279d90ef257d72ab17644c74cceb5503c58f234d17a92baa9bdadb54c
[INFO] checking ranafge/rust_async_await against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Franafge%2Frust_async_await" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ranafge/rust_async_await on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ranafge/rust_async_await
[INFO] finished tweaking git repo https://github.com/ranafge/rust_async_await
[INFO] tweaked toml for git repo https://github.com/ranafge/rust_async_await written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/ranafge/rust_async_await 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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b80e0124c9b471ae19f5b394407ce1e78234abc3e463c5ed22c9dac45fdcd50b
[INFO] running `Command { std: "docker" "start" "-a" "b80e0124c9b471ae19f5b394407ce1e78234abc3e463c5ed22c9dac45fdcd50b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b80e0124c9b471ae19f5b394407ce1e78234abc3e463c5ed22c9dac45fdcd50b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b80e0124c9b471ae19f5b394407ce1e78234abc3e463c5ed22c9dac45fdcd50b", kill_on_drop: false }`
[INFO] [stdout] b80e0124c9b471ae19f5b394407ce1e78234abc3e463c5ed22c9dac45fdcd50b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3cae3d16ce201b375274ff9edf34748f5ff0134888d820950f7f4c8a0612ca17
[INFO] running `Command { std: "docker" "start" "-a" "3cae3d16ce201b375274ff9edf34748f5ff0134888d820950f7f4c8a0612ca17", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.70
[INFO] [stderr]    Compiling libc v0.2.151
[INFO] [stderr]    Compiling futures-core v0.3.29
[INFO] [stderr]    Compiling futures-channel v0.3.29
[INFO] [stderr]    Compiling futures-util v0.3.29
[INFO] [stderr]     Checking futures-sink v0.3.29
[INFO] [stderr]     Checking async_await v0.1.0 (/opt/rustwide/workdir/async_await)
[INFO] [stderr]     Checking rust_futures_for_string v0.1.0 (/opt/rustwide/workdir/rust_futures_for_string)
[INFO] [stdout] warning: unused variable: `cx`
[INFO] [stdout]  --> rust_futures_for_string/src/lib.rs:8:45
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn poll(self: std::pin::Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> std::task::Poll<Self::Output> {
[INFO] [stdout]   |                                             ^^ help: if this is intentional, prefix it with an underscore: `_cx`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]    Compiling syn v2.0.40
[INFO] [stderr]     Checking parking_lot_core v0.9.9
[INFO] [stderr]     Checking mio v0.8.10
[INFO] [stderr]     Checking signal-hook-registry v1.4.1
[INFO] [stderr]     Checking socket2 v0.5.5
[INFO] [stderr]     Checking num_cpus v1.16.0
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]    Compiling futures-macro v0.3.29
[INFO] [stderr]    Compiling tokio-macros v2.2.0
[INFO] [stderr]     Checking tokio v1.35.0
[INFO] [stderr]     Checking futures-executor v0.3.29
[INFO] [stderr]     Checking futures v0.3.29
[INFO] [stderr]     Checking firstchapter_asyncawait v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 17.97s
[INFO] running `Command { std: "docker" "inspect" "3cae3d16ce201b375274ff9edf34748f5ff0134888d820950f7f4c8a0612ca17", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3cae3d16ce201b375274ff9edf34748f5ff0134888d820950f7f4c8a0612ca17", kill_on_drop: false }`
[INFO] [stdout] 3cae3d16ce201b375274ff9edf34748f5ff0134888d820950f7f4c8a0612ca17