[INFO] cloning repository https://github.com/jtgeibel/jtg-twitter-streams
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jtgeibel/jtg-twitter-streams" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjtgeibel%2Fjtg-twitter-streams", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjtgeibel%2Fjtg-twitter-streams'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0006dd2f4db9020fc70f5f3141a69323d057e155
[INFO] documenting jtgeibel/jtg-twitter-streams 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%2Fjtgeibel%2Fjtg-twitter-streams" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jtgeibel/jtg-twitter-streams 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/jtgeibel/jtg-twitter-streams
[INFO] finished tweaking git repo https://github.com/jtgeibel/jtg-twitter-streams
[INFO] tweaked toml for git repo https://github.com/jtgeibel/jtg-twitter-streams written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/jtgeibel/jtg-twitter-streams 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 51b939740318c5956a1883d07248903ef3ba8d52959331a5a9e3a0873c7d6ff1
[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" "51b939740318c5956a1883d07248903ef3ba8d52959331a5a9e3a0873c7d6ff1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "51b939740318c5956a1883d07248903ef3ba8d52959331a5a9e3a0873c7d6ff1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "51b939740318c5956a1883d07248903ef3ba8d52959331a5a9e3a0873c7d6ff1", kill_on_drop: false }`
[INFO] [stdout] 51b939740318c5956a1883d07248903ef3ba8d52959331a5a9e3a0873c7d6ff1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] [stdout] c3faa3cf241a8ae8418c7c023def573484244b47b1ef10608012f72d7e2d6199
[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" "c3faa3cf241a8ae8418c7c023def573484244b47b1ef10608012f72d7e2d6199", 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.7
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]     Checking tower-service v0.3.0-alpha.1
[INFO] [stderr]     Checking ucd-util v0.1.5
[INFO] [stderr]    Compiling palette v0.4.1
[INFO] [stderr]     Checking utf8-ranges v1.0.4
[INFO] [stderr]     Checking serde v0.9.15
[INFO] [stderr]     Checking float-ord v0.2.0
[INFO] [stderr]     Checking itoa v0.3.4
[INFO] [stderr]     Checking svg v0.6.0
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling cmake v0.1.42
[INFO] [stderr]    Compiling servo-fontconfig-sys v4.0.7
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking getrandom v0.1.13
[INFO] [stderr]     Checking memmap v0.7.0
[INFO] [stderr]     Checking dirs v1.0.5
[INFO] [stderr]     Checking deflate v0.7.20
[INFO] [stderr]     Checking jpeg-decoder v0.1.16
[INFO] [stderr]     Checking stb_truetype v0.3.0
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]    Compiling memoffset v0.5.2
[INFO] [stderr]     Checking flate2 v1.0.12
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]    Compiling syn v0.14.9
[INFO] [stderr]     Checking crypto-mac v0.7.0
[INFO] [stderr]     Checking block-buffer v0.7.3
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking native-tls v0.2.3
[INFO] [stderr]     Checking http-body v0.2.0-alpha.1
[INFO] [stderr]     Checking sha-1 v0.8.1
[INFO] [stderr]     Checking png v0.15.0
[INFO] [stderr]     Checking hmac v0.7.1
[INFO] [stderr]    Compiling servo-freetype-sys v4.0.5
[INFO] [stderr]    Compiling expat-sys v2.1.6
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking crossbeam-epoch v0.8.0
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking crossbeam-deque v0.7.2
[INFO] [stderr]     Checking freetype v0.4.1
[INFO] [stderr]     Checking servo-fontconfig v0.4.0
[INFO] [stderr]     Checking euclid v0.20.3
[INFO] [stderr]     Checking ordered-float v1.0.2
[INFO] [stderr]     Checking approx v0.3.2
[INFO] [stderr]     Checking num-traits v0.1.43
[INFO] [stderr]     Checking rusttype v0.8.1
[INFO] [stderr]     Checking chrono v0.4.9
[INFO] [stderr]     Checking regex v0.2.11
[INFO] [stderr]     Checking image v0.22.3
[INFO] [stderr]     Checking lyon_geom v0.14.1
[INFO] [stderr]     Checking serde_json v0.9.10
[INFO] [stderr]     Checking lyon_path v0.14.0
[INFO] [stderr]     Checking font-kit v0.4.0
[INFO] [stderr]     Checking sentiment v0.1.1
[INFO] [stderr]    Compiling palette_derive v0.4.1
[INFO] [stderr]     Checking serde_json v1.0.41
[INFO] [stderr]    Compiling toml v0.5.5
[INFO] [stderr]    Compiling proc-macro-crate v0.1.4
[INFO] [stderr]     Checking plotters v0.2.11
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling tracing-attributes v0.1.5
[INFO] [stderr]    Compiling tokio-macros v0.2.0-alpha.5
[INFO] [stderr]    Compiling oauth1-request-derive v0.3.1
[INFO] [stderr]    Compiling pin-project v0.3.5
[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 tracing v0.1.10
[INFO] [stderr]     Checking oauth1-request v0.3.0
[INFO] [stderr]     Checking pin-project v0.4.0-alpha.11
[INFO] [stderr]     Checking tokio-io v0.2.0-alpha.5
[INFO] [stderr]     Checking tokio-codec v0.2.0-alpha.5
[INFO] [stderr]     Checking tower-make v0.3.0-alpha.2
[INFO] [stderr]     Checking tokio-tls v0.3.0-alpha.5
[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" "c3faa3cf241a8ae8418c7c023def573484244b47b1ef10608012f72d7e2d6199", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3faa3cf241a8ae8418c7c023def573484244b47b1ef10608012f72d7e2d6199", kill_on_drop: false }`
[INFO] [stdout] c3faa3cf241a8ae8418c7c023def573484244b47b1ef10608012f72d7e2d6199