[INFO] fetching crate bst 0.0.1...
[INFO] documenting bst-0.0.1 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate bst 0.0.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate bst 0.0.1 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 crates.io crate bst 0.0.1
[INFO] finished tweaking crates.io crate bst 0.0.1
[INFO] tweaked toml for crates.io crate bst 0.0.1 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: dependency (ordered_iter) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 8bd7484a62dff3349b88082ed7c157ce7a58b195a9ac7718eac835cec741fb23
[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" "8bd7484a62dff3349b88082ed7c157ce7a58b195a9ac7718eac835cec741fb23", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8bd7484a62dff3349b88082ed7c157ce7a58b195a9ac7718eac835cec741fb23", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bd7484a62dff3349b88082ed7c157ce7a58b195a9ac7718eac835cec741fb23", kill_on_drop: false }`
[INFO] [stdout] 8bd7484a62dff3349b88082ed7c157ce7a58b195a9ac7718eac835cec741fb23
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 0a7ed9eb12ca1951f77aca374f3c7c9d352930ca953e13e5c55bdb49e3256bd3
[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" "0a7ed9eb12ca1951f77aca374f3c7c9d352930ca953e13e5c55bdb49e3256bd3", kill_on_drop: false }`
[INFO] [stderr] warning: dependency (ordered_iter) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr]     Checking bit-vec v0.6.2
[INFO] [stderr]     Checking compare v0.1.0
[INFO] [stderr]     Checking bit-set v0.5.2
[INFO] [stderr]     Checking ordered_iter v0.1.2
[INFO] [stderr]  Documenting bst v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:200:5
[INFO] [stdout]     |
[INFO] [stdout] 200 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:229:5
[INFO] [stdout]     |
[INFO] [stdout] 229 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:254:5
[INFO] [stdout]     |
[INFO] [stdout] 254 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:278:5
[INFO] [stdout]     |
[INFO] [stdout] 278 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:330:5
[INFO] [stdout]     |
[INFO] [stdout] 330 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:381:5
[INFO] [stdout]     |
[INFO] [stdout] 381 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:406:5
[INFO] [stdout]     |
[INFO] [stdout] 406 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:421:5
[INFO] [stdout]     |
[INFO] [stdout] 421 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:437:5
[INFO] [stdout]     |
[INFO] [stdout] 437 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:459:5
[INFO] [stdout]     |
[INFO] [stdout] 459 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:488:5
[INFO] [stdout]     |
[INFO] [stdout] 488 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:514:5
[INFO] [stdout]     |
[INFO] [stdout] 514 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:543:5
[INFO] [stdout]     |
[INFO] [stdout] 543 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/map.rs:566:5
[INFO] [stdout]     |
[INFO] [stdout] 566 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:134:5
[INFO] [stdout]     |
[INFO] [stdout] 134 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:161:5
[INFO] [stdout]     |
[INFO] [stdout] 161 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:198:5
[INFO] [stdout]     |
[INFO] [stdout] 198 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:266:5
[INFO] [stdout]     |
[INFO] [stdout] 266 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:298:5
[INFO] [stdout]     |
[INFO] [stdout] 298 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:327:5
[INFO] [stdout]     |
[INFO] [stdout] 327 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:356:5
[INFO] [stdout]     |
[INFO] [stdout] 356 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:380:5
[INFO] [stdout]     |
[INFO] [stdout] 380 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:395:5
[INFO] [stdout]     |
[INFO] [stdout] 395 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:411:5
[INFO] [stdout]     |
[INFO] [stdout] 411 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:430:5
[INFO] [stdout]     |
[INFO] [stdout] 430 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:454:5
[INFO] [stdout]     |
[INFO] [stdout] 454 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:475:5
[INFO] [stdout]     |
[INFO] [stdout] 475 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:520:5
[INFO] [stdout]     |
[INFO] [stdout] 520 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:540:5
[INFO] [stdout]     |
[INFO] [stdout] 540 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:562:5
[INFO] [stdout]     |
[INFO] [stdout] 562 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:698:1
[INFO] [stdout]     |
[INFO] [stdout] 698 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:726:1
[INFO] [stdout]     |
[INFO] [stdout] 726 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:754:1
[INFO] [stdout]     |
[INFO] [stdout] 754 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/set.rs:782:1
[INFO] [stdout]     |
[INFO] [stdout] 782 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[unstable(feature = "name", reason = "...", issue = "N")]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:34:1
[INFO] [stdout]    |
[INFO] [stdout] 34 | #![feature(box_patterns, box_syntax)]
[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:35:1
[INFO] [stdout]    |
[INFO] [stdout] 35 | #![feature(core)]
[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:36:1
[INFO] [stdout]    |
[INFO] [stdout] 36 | #![feature(unboxed_closures)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 38 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `bst`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name bst src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="ordered_iter"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern compare=/opt/rustwide/target/debug/deps/libcompare-ffc46e99f07fd8c7.rmeta --extern ordered_iter=/opt/rustwide/target/debug/deps/libordered_iter-6b58766f165b30ad.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "0a7ed9eb12ca1951f77aca374f3c7c9d352930ca953e13e5c55bdb49e3256bd3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0a7ed9eb12ca1951f77aca374f3c7c9d352930ca953e13e5c55bdb49e3256bd3", kill_on_drop: false }`
[INFO] [stdout] 0a7ed9eb12ca1951f77aca374f3c7c9d352930ca953e13e5c55bdb49e3256bd3