[INFO] fetching crate ngram_iter 0.1.0...
[INFO] testing ngram_iter-0.1.0 against 1.91.0 for beta-1.92-2
[INFO] extracting crate ngram_iter 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate ngram_iter 0.1.0
[INFO] finished tweaking crates.io crate ngram_iter 0.1.0
[INFO] tweaked toml for crates.io crate ngram_iter 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate ngram_iter 0.1.0 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 715ddc792898bf4fae33d7a5c41504a1f8525de5eca2e82e72a15dbc95eeb1ca
[INFO] running `Command { std: "docker" "start" "-a" "715ddc792898bf4fae33d7a5c41504a1f8525de5eca2e82e72a15dbc95eeb1ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "715ddc792898bf4fae33d7a5c41504a1f8525de5eca2e82e72a15dbc95eeb1ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "715ddc792898bf4fae33d7a5c41504a1f8525de5eca2e82e72a15dbc95eeb1ca", kill_on_drop: false }`
[INFO] [stdout] 715ddc792898bf4fae33d7a5c41504a1f8525de5eca2e82e72a15dbc95eeb1ca
[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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1d9c51735f7846d05c8f0e812417ee070ee3beaa5513255bca0bd1d58fc35af3
[INFO] running `Command { std: "docker" "start" "-a" "1d9c51735f7846d05c8f0e812417ee070ee3beaa5513255bca0bd1d58fc35af3", kill_on_drop: false }`
[INFO] [stderr]    Compiling ngram_iter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(maybe_uninit_uninit_array)]
[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:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(maybe_uninit_array_assume_init)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `maybe_uninit_uninit_array`
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(maybe_uninit_uninit_array)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no function or associated item named `uninit_array` found for union `MaybeUninit<T>` in the current scope
[INFO] [stdout]   --> src/iter/mod.rs:53:57
[INFO] [stdout]    |
[INFO] [stdout] 53 |         let mut out: [MaybeUninit<T>; N] = MaybeUninit::uninit_array();
[INFO] [stdout]    |                                                         ^^^^^^^^^^^^ function or associated item not found in `MaybeUninit<_>`
[INFO] [stdout]    |
[INFO] [stdout] note: if you're trying to build a new `MaybeUninit<_>` consider using one of the following associated functions:
[INFO] [stdout]       MaybeUninit::<T>::new
[INFO] [stdout]       MaybeUninit::<T>::uninit
[INFO] [stdout]       MaybeUninit::<T>::zeroed
[INFO] [stdout]   --> /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/mem/maybe_uninit.rs:307:5
[INFO] [stdout] help: there is an associated function `uninit` with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 53 -         let mut out: [MaybeUninit<T>; N] = MaybeUninit::uninit_array();
[INFO] [stdout] 53 +         let mut out: [MaybeUninit<T>; N] = MaybeUninit::uninit();
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ngram_iter` (lib) due to 4 previous errors
[INFO] running `Command { std: "docker" "inspect" "1d9c51735f7846d05c8f0e812417ee070ee3beaa5513255bca0bd1d58fc35af3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1d9c51735f7846d05c8f0e812417ee070ee3beaa5513255bca0bd1d58fc35af3", kill_on_drop: false }`
[INFO] [stdout] 1d9c51735f7846d05c8f0e812417ee070ee3beaa5513255bca0bd1d58fc35af3