[INFO] cloning repository https://github.com/oconnor663/happy_eyeballs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/oconnor663/happy_eyeballs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foconnor663%2Fhappy_eyeballs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foconnor663%2Fhappy_eyeballs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5323d3f6562aac9fbec242b1e0b5306b7ac24fb6
[INFO] documenting oconnor663/happy_eyeballs against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Foconnor663%2Fhappy_eyeballs" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/oconnor663/happy_eyeballs on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/oconnor663/happy_eyeballs
[INFO] finished tweaking git repo https://github.com/oconnor663/happy_eyeballs
[INFO] tweaked toml for git repo https://github.com/oconnor663/happy_eyeballs written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/oconnor663/happy_eyeballs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 783c63c95ff0b6102f090af98f0b1e0d0100de28fd76777fd27cf6658488958d
[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" "783c63c95ff0b6102f090af98f0b1e0d0100de28fd76777fd27cf6658488958d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "783c63c95ff0b6102f090af98f0b1e0d0100de28fd76777fd27cf6658488958d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "783c63c95ff0b6102f090af98f0b1e0d0100de28fd76777fd27cf6658488958d", kill_on_drop: false }`
[INFO] [stdout] 783c63c95ff0b6102f090af98f0b1e0d0100de28fd76777fd27cf6658488958d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a0f510d69dd719ad23686e4d10015bf8603ae55c4ccbad4ac871fc65f9ebda95
[INFO] running `Command { std: "docker" "start" "-a" "a0f510d69dd719ad23686e4d10015bf8603ae55c4ccbad4ac871fc65f9ebda95", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]    Compiling proc-macro2 v1.0.1
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]     Checking lazy_static v1.3.0
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling getrandom v0.1.10
[INFO] [stderr]    Compiling syn v1.0.3
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking ppv-lite86 v0.2.5
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]     Checking async-task v1.0.0
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking rand_core v0.5.0
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.0
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]    Compiling proc-macro-hack v0.5.9
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-select-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 stable 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" "a0f510d69dd719ad23686e4d10015bf8603ae55c4ccbad4ac871fc65f9ebda95", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a0f510d69dd719ad23686e4d10015bf8603ae55c4ccbad4ac871fc65f9ebda95", kill_on_drop: false }`
[INFO] [stdout] a0f510d69dd719ad23686e4d10015bf8603ae55c4ccbad4ac871fc65f9ebda95