[INFO] fetching crate facade 0.0.0...
[INFO] documenting facade-0.0.0 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate facade 0.0.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate facade 0.0.0 on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate facade 0.0.0
[INFO] finished tweaking crates.io crate facade 0.0.0
[INFO] tweaked toml for crates.io crate facade 0.0.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--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 futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded warp v0.1.23
[INFO] [stderr]   Downloaded futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-timer v0.2.1
[INFO] [stderr]   Downloaded facade-protocol v0.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b91306a31383d9cc2b80f7708d96dcfa0ba4d1d26f648a56c44152383811209c
[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" "b91306a31383d9cc2b80f7708d96dcfa0ba4d1d26f648a56c44152383811209c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b91306a31383d9cc2b80f7708d96dcfa0ba4d1d26f648a56c44152383811209c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b91306a31383d9cc2b80f7708d96dcfa0ba4d1d26f648a56c44152383811209c", kill_on_drop: false }`
[INFO] [stdout] b91306a31383d9cc2b80f7708d96dcfa0ba4d1d26f648a56c44152383811209c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "RUSTDOCFLAGS=--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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 77f413032aa460b4398ca65b773e1c256874b8e5043f9099b908cdd2df808bb2
[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" "77f413032aa460b4398ca65b773e1c256874b8e5043f9099b908cdd2df808bb2", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking urlencoding v1.1.1
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]     Checking buf_redux v0.8.4
[INFO] [stderr]     Checking twoway v0.1.8
[INFO] [stderr]     Checking input_buffer v0.2.0
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stderr]     Checking headers-core v0.1.1
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking config v0.9.3
[INFO] [stderr]     Checking bigdecimal v0.1.2
[INFO] [stderr]     Checking phf_shared v0.7.24
[INFO] [stderr]     Checking headers v0.2.3
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking phf v0.7.24
[INFO] [stderr]     Checking tungstenite v0.9.2
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking facade-protocol v0.1.0
[INFO] [stderr]    Compiling phf_codegen v0.7.24
[INFO] [stderr]    Compiling mime_guess v1.8.8
[INFO] [stderr]     Checking hyper v0.12.35
[INFO] [stderr]     Checking multipart v0.16.1
[INFO] [stderr]     Checking warp v0.1.23
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `futures-util-preview`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "77f413032aa460b4398ca65b773e1c256874b8e5043f9099b908cdd2df808bb2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77f413032aa460b4398ca65b773e1c256874b8e5043f9099b908cdd2df808bb2", kill_on_drop: false }`
[INFO] [stdout] 77f413032aa460b4398ca65b773e1c256874b8e5043f9099b908cdd2df808bb2