[INFO] fetching crate drone 0.14.0...
[INFO] documenting drone-0.14.0 against 1.75.0 for beta-1.76-rustdoc-1
[INFO] extracting crate drone 0.14.0 into /workspace/builds/worker-3-tc1/source
[INFO] validating manifest of crates.io crate drone 0.14.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-3-tc1/source/rust-toolchain
[INFO] started tweaking crates.io crate drone 0.14.0
[INFO] finished tweaking crates.io crate drone 0.14.0
[INFO] tweaked toml for crates.io crate drone 0.14.0 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate crates.io crate drone 0.14.0 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" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded typenum v1.13.0
[INFO] [stderr]   Downloaded quick-error v2.0.0
[INFO] [stderr]   Downloaded thiserror v1.0.24
[INFO] [stderr]   Downloaded handlebars v3.5.4
[INFO] [stderr]   Downloaded anyhow v1.0.40
[INFO] [stderr]   Downloaded tempfile v3.2.0
[INFO] [stderr]   Downloaded signal-hook v0.2.3
[INFO] [stderr]   Downloaded thiserror-impl v1.0.24
[INFO] [stderr]   Downloaded drone-config v0.14.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 82d5b1b42ec1ad2eb02f043a1c83f9a1d811321f156891b5b59e4b00cf50232c
[INFO] running `Command { std: "docker" "start" "-a" "82d5b1b42ec1ad2eb02f043a1c83f9a1d811321f156891b5b59e4b00cf50232c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "82d5b1b42ec1ad2eb02f043a1c83f9a1d811321f156891b5b59e4b00cf50232c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "82d5b1b42ec1ad2eb02f043a1c83f9a1d811321f156891b5b59e4b00cf50232c", kill_on_drop: false }`
[INFO] [stdout] 82d5b1b42ec1ad2eb02f043a1c83f9a1d811321f156891b5b59e4b00cf50232c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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=warn" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 31299a35807e8699b751865d67747ab6a5c1e2c3a3148301a6c72c987f75e888
[INFO] running `Command { std: "docker" "start" "-a" "31299a35807e8699b751865d67747ab6a5c1e2c3a3148301a6c72c987f75e888", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling syn v1.0.69
[INFO] [stderr]    Compiling libc v0.2.93
[INFO] [stderr]    Compiling serde_derive v1.0.125
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling serde v1.0.125
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]     Checking aho-corasick v0.7.15
[INFO] [stderr]     Checking regex-syntax v0.6.23
[INFO] [stderr]    Compiling anyhow v1.0.40
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling pest_meta v2.1.3
[INFO] [stderr]     Checking rand_core v0.6.2
[INFO] [stderr]     Checking dirs v1.0.5
[INFO] [stderr]    Compiling heck v0.3.2
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]     Checking term v0.5.2
[INFO] [stderr]     Checking signal-hook-registry v1.3.0
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking quick-error v2.0.0
[INFO] [stderr]     Checking termcolor v1.1.2
[INFO] [stderr]     Checking encode_unicode v0.3.6
[INFO] [stderr]     Checking signal-hook v0.2.3
[INFO] [stderr]     Checking tempfile v3.2.0
[INFO] [stderr]     Checking regex v1.4.5
[INFO] [stderr]     Checking Inflector v0.11.4
[INFO] [stderr]     Checking env_logger v0.8.3
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]    Compiling thiserror-impl v1.0.24
[INFO] [stderr]     Checking thiserror v1.0.24
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]     Checking bstr v0.2.15
[INFO] [stderr]     Checking toml v0.5.8
[INFO] [stderr]     Checking csv v1.1.6
[INFO] [stderr]     Checking drone-config v0.14.0
[INFO] [stderr]     Checking handlebars v3.5.4
[INFO] [stderr]     Checking prettytable-rs v0.8.0
[INFO] [stderr]  Documenting drone v0.14.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking drone v0.14.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]   --> src/lib.rs:31:12
[INFO] [stdout]    |
[INFO] [stdout] 31 | #![feature(generators)]
[INFO] [stdout]    |            ^^^^^^^^^^ feature has been removed
[INFO] [stdout]    |
[INFO] [stdout]    = note: renamed to `coroutines`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `drone`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/1.75.0-x86_64-unknown-linux-gnu/bin/rustdoc --edition=2018 --crate-type lib --crate-name drone src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=fa0ce1c0640e23be -L dependency=/opt/rustwide/target/debug/deps --extern inflector=/opt/rustwide/target/debug/deps/libinflector-b77dcd30c205357a.rmeta --extern ansi_term=/opt/rustwide/target/debug/deps/libansi_term-c89d4dbd07eea222.rmeta --extern anyhow=/opt/rustwide/target/debug/deps/libanyhow-c1550c83d6168395.rmeta --extern drone_config=/opt/rustwide/target/debug/deps/libdrone_config-e1aaf688887ac7b5.rmeta --extern env_logger=/opt/rustwide/target/debug/deps/libenv_logger-19c38406bdde25f7.rmeta --extern handlebars=/opt/rustwide/target/debug/deps/libhandlebars-1ef249a3d3bfa8e8.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-2a0e28923fdf0fe2.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-f0223f3a435bc936.rmeta --extern prettytable=/opt/rustwide/target/debug/deps/libprettytable-f512e50fdc5968b2.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-6da6c8813be7cd2b.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-58d6588031c22243.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-54f91db10add4788.rmeta --extern signal_hook=/opt/rustwide/target/debug/deps/libsignal_hook-18b1e3f636dbeaf3.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-ae5354b23bd5538c.rmeta --extern tempfile=/opt/rustwide/target/debug/deps/libtempfile-0f3ba4693aaf6484.rmeta --extern thiserror=/opt/rustwide/target/debug/deps/libthiserror-4e65caea02b8ae8a.rmeta --extern toml=/opt/rustwide/target/debug/deps/libtoml-199eefa832fd2537.rmeta --extern walkdir=/opt/rustwide/target/debug/deps/libwalkdir-5e19c5a4785aba60.rmeta --cap-lints=warn --crate-version 0.14.0` (exit status: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]   --> src/lib.rs:31:12
[INFO] [stdout]    |
[INFO] [stdout] 31 | #![feature(generators)]
[INFO] [stdout]    |            ^^^^^^^^^^ feature has been removed
[INFO] [stdout]    |
[INFO] [stdout]    = note: renamed to `coroutines`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved imports `std::ops::Generator`, `std::ops::GeneratorState`
[INFO] [stdout]  --> src/heap/trace.rs:7:11
[INFO] [stdout]   |
[INFO] [stdout] 7 |     ops::{Generator, GeneratorState},
[INFO] [stdout]   |           ^^^^^^^^^  ^^^^^^^^^^^^^^ no `GeneratorState` in `ops`
[INFO] [stdout]   |           |
[INFO] [stdout]   |           no `Generator` in `ops`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::ops::Generator`
[INFO] [stdout]  --> src/log/dso.rs:5:11
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::{ops::Generator, pin::Pin};
[INFO] [stdout]   |           ^^^^^^^^^^^^^^ no `Generator` in `ops`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::ops::Generator`
[INFO] [stdout]  --> src/log/swo.rs:5:11
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::{ops::Generator, pin::Pin};
[INFO] [stdout]   |           ^^^^^^^^^^^^^^ no `Generator` in `ops`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved imports `std::ops::Generator`, `std::ops::GeneratorState`
[INFO] [stdout]   --> src/log/mod.rs:14:11
[INFO] [stdout]    |
[INFO] [stdout] 14 |     ops::{Generator, GeneratorState},
[INFO] [stdout]    |           ^^^^^^^^^  ^^^^^^^^^^^^^^ no `GeneratorState` in `ops`
[INFO] [stdout]    |           |
[INFO] [stdout]    |           no `Generator` in `ops`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:28:1
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(bool_to_option)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:29:1
[INFO] [stdout]    |
[INFO] [stdout] 29 | #![feature(exhaustive_patterns)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:30:1
[INFO] [stdout]    |
[INFO] [stdout] 30 | #![feature(generator_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:31:1
[INFO] [stdout]    |
[INFO] [stdout] 31 | #![feature(generators)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:32:1
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![feature(never_type)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/heap/trace.rs:187:21
[INFO] [stdout]     |
[INFO] [stdout] 187 |                     yield Packet::Alloc { size };
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/heap/trace.rs:200:21
[INFO] [stdout]     |
[INFO] [stdout] 200 |                     yield Packet::Dealloc { size };
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/heap/trace.rs:214:21
[INFO] [stdout]     |
[INFO] [stdout] 214 |                     yield Packet::Grow { old_size, new_size };
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/heap/trace.rs:228:21
[INFO] [stdout]     |
[INFO] [stdout] 228 |                     yield Packet::Shrink { old_size, new_size };
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/dso.rs:19:24
[INFO] [stdout]    |
[INFO] [stdout] 19 |                 byte = yield;
[INFO] [stdout]    |                        ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/dso.rs:23:34
[INFO] [stdout]    |
[INFO] [stdout] 23 |                     payload.push(yield);
[INFO] [stdout]    |                                  ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/dso.rs:34:20
[INFO] [stdout]    |
[INFO] [stdout] 34 |             byte = yield;
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/swo.rs:33:36
[INFO] [stdout]    |
[INFO] [stdout] 33 |                         let byte = yield;
[INFO] [stdout]    |                                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/swo.rs:57:36
[INFO] [stdout]    |
[INFO] [stdout] 57 |                         let byte = yield;
[INFO] [stdout]    |                                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]   --> src/log/swo.rs:89:36
[INFO] [stdout]    |
[INFO] [stdout] 89 |                         let byte = yield;
[INFO] [stdout]    |                                    ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/log/swo.rs:114:38
[INFO] [stdout]     |
[INFO] [stdout] 114 |                         payload.push(yield);
[INFO] [stdout]     |                                      ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: yield syntax is experimental
[INFO] [stdout]    --> src/log/swo.rs:119:28
[INFO] [stdout]     |
[INFO] [stdout] 119 |                 bytes.push(yield);
[INFO] [stdout]     |                            ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:28:12
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(bool_to_option)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 | #![feature(generator_trait)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `bool_to_option` has been stable since 1.62.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:28:12
[INFO] [stdout]    |
[INFO] [stdout] 28 | #![feature(bool_to_option)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `generator_trait`
[INFO] [stdout]   --> src/lib.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 | #![feature(generator_trait)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 25 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554, E0557, E0635, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `drone` (lib) due to 26 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "31299a35807e8699b751865d67747ab6a5c1e2c3a3148301a6c72c987f75e888", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31299a35807e8699b751865d67747ab6a5c1e2c3a3148301a6c72c987f75e888", kill_on_drop: false }`
[INFO] [stdout] 31299a35807e8699b751865d67747ab6a5c1e2c3a3148301a6c72c987f75e888
