[INFO] fetching crate cow 0.0.8...
[INFO] documenting cow-0.0.8 against 1.69.0 for beta-1.70-rustdoc-1
[INFO] extracting crate cow 0.0.8 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate cow 0.0.8 on toolchain 1.69.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.69.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cow 0.0.8
[INFO] finished tweaking crates.io crate cow 0.0.8
[INFO] tweaked toml for crates.io crate cow 0.0.8 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" __CARGO_TEST_CHANNEL_OVERRIDE_DO_NOT_USE_THIS="nightly" "/workspace/cargo-home/bin/cargo" "+1.69.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.69.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: path `/workspace/builds/worker-2-tc1/source/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+1.69.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b0eafc27ec94f126a7ed88b2f9280d08cd7e795f68f007f8d94e93c5a6420ab0
[INFO] running `Command { std: "docker" "start" "-a" "b0eafc27ec94f126a7ed88b2f9280d08cd7e795f68f007f8d94e93c5a6420ab0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b0eafc27ec94f126a7ed88b2f9280d08cd7e795f68f007f8d94e93c5a6420ab0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b0eafc27ec94f126a7ed88b2f9280d08cd7e795f68f007f8d94e93c5a6420ab0", kill_on_drop: false }`
[INFO] [stdout] b0eafc27ec94f126a7ed88b2f9280d08cd7e795f68f007f8d94e93c5a6420ab0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:5ff2268d62e97bff2cde7d5815dd6ed5b47097566f13b8d0ca110b04b60e07ed" "/opt/rustwide/cargo-home/bin/cargo" "+1.69.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e87e32e9a0aba057e71ef1d6aea4696e139b9bcf1b6e4c4619c1d2a451dafda
[INFO] running `Command { std: "docker" "start" "-a" "6e87e32e9a0aba057e71ef1d6aea4696e139b9bcf1b6e4c4619c1d2a451dafda", kill_on_drop: false }`
[INFO] [stderr] warning: path `/opt/rustwide/workdir/src/cow.rs` was erroneously implicitly accepted for library `cow`,
[INFO] [stderr] please rename the file to `src/lib.rs` or set lib.path in Cargo.toml
[INFO] [stderr]  Documenting cow v0.0.8 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0463]: can't find crate for `collections`
[INFO] [stdout]  --> src/cow.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | extern crate collections;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: malformed `unstable` attribute input
[INFO] [stdout]    --> src/trie/map.rs:168:5
[INFO] [stdout]     |
[INFO] [stdout] 168 |     #[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/trie/map.rs:199:5
[INFO] [stdout]     |
[INFO] [stdout] 199 |     #[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/trie/map.rs:209:5
[INFO] [stdout]     |
[INFO] [stdout] 209 |     #[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/trie/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/trie/map.rs:253:5
[INFO] [stdout]     |
[INFO] [stdout] 253 |     #[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/trie/map.rs:269:5
[INFO] [stdout]     |
[INFO] [stdout] 269 |     #[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/trie/map.rs:285:5
[INFO] [stdout]     |
[INFO] [stdout] 285 |     #[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/trie/map.rs:310:5
[INFO] [stdout]     |
[INFO] [stdout] 310 |     #[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/trie/map.rs:343:5
[INFO] [stdout]     |
[INFO] [stdout] 343 |     #[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/trie/map.rs:367:5
[INFO] [stdout]     |
[INFO] [stdout] 367 |     #[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/trie/map.rs:400:5
[INFO] [stdout]     |
[INFO] [stdout] 400 |     #[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/trie/map.rs:427:5
[INFO] [stdout]     |
[INFO] [stdout] 427 |     #[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/trie/map.rs:455:5
[INFO] [stdout]     |
[INFO] [stdout] 455 |     #[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/trie/set.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     #[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/trie/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/trie/set.rs:196:5
[INFO] [stdout]     |
[INFO] [stdout] 196 |     #[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/trie/set.rs:222:5
[INFO] [stdout]     |
[INFO] [stdout] 222 |     #[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/trie/set.rs:245:5
[INFO] [stdout]     |
[INFO] [stdout] 245 |     #[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/trie/set.rs:268:5
[INFO] [stdout]     |
[INFO] [stdout] 268 |     #[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/trie/set.rs:286:5
[INFO] [stdout]     |
[INFO] [stdout] 286 |     #[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/trie/set.rs:301:5
[INFO] [stdout]     |
[INFO] [stdout] 301 |     #[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/trie/set.rs:317:5
[INFO] [stdout]     |
[INFO] [stdout] 317 |     #[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/trie/set.rs:332:5
[INFO] [stdout]     |
[INFO] [stdout] 332 |     #[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/trie/set.rs:355:5
[INFO] [stdout]     |
[INFO] [stdout] 355 |     #[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/trie/set.rs:377:5
[INFO] [stdout]     |
[INFO] [stdout] 377 |     #[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/trie/set.rs:402:5
[INFO] [stdout]     |
[INFO] [stdout] 402 |     #[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/trie/set.rs:422:5
[INFO] [stdout]     |
[INFO] [stdout] 422 |     #[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/trie/set.rs:442:5
[INFO] [stdout]     |
[INFO] [stdout] 442 |     #[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/trie/set.rs:464:1
[INFO] [stdout]     |
[INFO] [stdout] 464 | #[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/trie/set.rs:487:1
[INFO] [stdout]     |
[INFO] [stdout] 487 | #[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/trie/set.rs:510:1
[INFO] [stdout]     |
[INFO] [stdout] 510 | #[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/trie/set.rs:533:1
[INFO] [stdout]     |
[INFO] [stdout] 533 | #[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/cow.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(core, alloc, collections, unboxed_closures, test, rand, hash)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:168:5
[INFO] [stdout]     |
[INFO] [stdout] 168 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:199:5
[INFO] [stdout]     |
[INFO] [stdout] 199 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:209:5
[INFO] [stdout]     |
[INFO] [stdout] 209 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:229:5
[INFO] [stdout]     |
[INFO] [stdout] 229 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:253:5
[INFO] [stdout]     |
[INFO] [stdout] 253 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:269:5
[INFO] [stdout]     |
[INFO] [stdout] 269 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:285:5
[INFO] [stdout]     |
[INFO] [stdout] 285 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:310:5
[INFO] [stdout]     |
[INFO] [stdout] 310 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:343:5
[INFO] [stdout]     |
[INFO] [stdout] 343 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:367:5
[INFO] [stdout]     |
[INFO] [stdout] 367 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:400:5
[INFO] [stdout]     |
[INFO] [stdout] 400 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:427:5
[INFO] [stdout]     |
[INFO] [stdout] 427 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/map.rs:455:5
[INFO] [stdout]     |
[INFO] [stdout] 455 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]   --> src/trie/set.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:134:5
[INFO] [stdout]     |
[INFO] [stdout] 134 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:196:5
[INFO] [stdout]     |
[INFO] [stdout] 196 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:222:5
[INFO] [stdout]     |
[INFO] [stdout] 222 |     #[unstable = "matches collection reform specification, waiting for dust to settle."]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:245:5
[INFO] [stdout]     |
[INFO] [stdout] 245 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:268:5
[INFO] [stdout]     |
[INFO] [stdout] 268 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:286:5
[INFO] [stdout]     |
[INFO] [stdout] 286 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:301:5
[INFO] [stdout]     |
[INFO] [stdout] 301 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:317:5
[INFO] [stdout]     |
[INFO] [stdout] 317 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:332:5
[INFO] [stdout]     |
[INFO] [stdout] 332 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:355:5
[INFO] [stdout]     |
[INFO] [stdout] 355 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:377:5
[INFO] [stdout]     |
[INFO] [stdout] 377 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:402:5
[INFO] [stdout]     |
[INFO] [stdout] 402 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:422:5
[INFO] [stdout]     |
[INFO] [stdout] 422 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:442:5
[INFO] [stdout]     |
[INFO] [stdout] 442 |     #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:464:1
[INFO] [stdout]     |
[INFO] [stdout] 464 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:487:1
[INFO] [stdout]     |
[INFO] [stdout] 487 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:510:1
[INFO] [stdout]     |
[INFO] [stdout] 510 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0734]: stability attributes may not be used outside of the standard library
[INFO] [stdout]    --> src/trie/set.rs:533:1
[INFO] [stdout]     |
[INFO] [stdout] 533 | #[unstable = "matches collection reform specification, waiting for dust to settle"]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 66 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0463, E0554, E0734.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `cow`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name cow src/cow.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=f3b73b739fc7dfa9 -L dependency=/opt/rustwide/target/debug/deps --extern rustc_serialize=/opt/rustwide/target/debug/deps/librustc_serialize-4f6d97d9bf0baf34.rmeta --cap-lints=warn --crate-version 0.0.8` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "6e87e32e9a0aba057e71ef1d6aea4696e139b9bcf1b6e4c4619c1d2a451dafda", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e87e32e9a0aba057e71ef1d6aea4696e139b9bcf1b6e4c4619c1d2a451dafda", kill_on_drop: false }`
[INFO] [stdout] 6e87e32e9a0aba057e71ef1d6aea4696e139b9bcf1b6e4c4619c1d2a451dafda
