[INFO] fetching crate nestor 0.1.0...
[INFO] testing nestor-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate nestor 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate nestor 0.1.0 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nestor 0.1.0
[INFO] finished tweaking crates.io crate nestor 0.1.0
[INFO] tweaked toml for crates.io crate nestor 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 220a1a0a6d2265e683a081b97e4fe67dd29532ed3a17917d7b7bec4ceaf58426
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "220a1a0a6d2265e683a081b97e4fe67dd29532ed3a17917d7b7bec4ceaf58426", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "220a1a0a6d2265e683a081b97e4fe67dd29532ed3a17917d7b7bec4ceaf58426", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "220a1a0a6d2265e683a081b97e4fe67dd29532ed3a17917d7b7bec4ceaf58426", kill_on_drop: false }`
[INFO] [stdout] 220a1a0a6d2265e683a081b97e4fe67dd29532ed3a17917d7b7bec4ceaf58426
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=warn" "-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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2a4f18f92603f94e285e854db3450d684558aa578896528d2e8da11eb63dea7c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "2a4f18f92603f94e285e854db3450d684558aa578896528d2e8da11eb63dea7c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling futures v0.1.30
[INFO] [stderr]    Compiling bufstream v0.1.4
[INFO] [stderr]    Compiling tokio-trace-core v0.1.0
[INFO] [stderr]    Compiling state v0.4.2
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling toml v0.4.10
[INFO] [stderr]    Compiling tokio-io v0.1.13
[INFO] [stderr]    Compiling tokio-executor v0.1.10
[INFO] [stderr]    Compiling tokio-sync v0.1.8
[INFO] [stderr]    Compiling tokio-timer v0.1.2
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling tokio-current-thread v0.1.7
[INFO] [stderr]    Compiling tokio-timer v0.2.13
[INFO] [stderr]    Compiling tokio-codec v0.1.2
[INFO] [stderr]    Compiling tokio-async-await v0.1.7
[INFO] [stderr]    Compiling tokio-mockstream v1.1.0
[INFO] [stderr]    Compiling tokio-tls v0.2.1
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/tokio-async-await-0.1.7/src/lib.rs:2:44
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(rust_2018_preview, async_await, await_macro, futures_api)]
[INFO] [stdout]   |                                            ^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: subsumed by `.await` syntax
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::await`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/tokio-async-await-0.1.7/src/lib.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 | pub use std::await as std_await;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^ no `await` in the root
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/tokio-async-await-0.1.7/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(rust_2018_preview, async_await, await_macro, futures_api)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tokio-async-await`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2a4f18f92603f94e285e854db3450d684558aa578896528d2e8da11eb63dea7c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a4f18f92603f94e285e854db3450d684558aa578896528d2e8da11eb63dea7c", kill_on_drop: false }`
[INFO] [stdout] 2a4f18f92603f94e285e854db3450d684558aa578896528d2e8da11eb63dea7c