[INFO] cloning repository https://github.com/AliasT/directory-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AliasT/directory-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAliasT%2Fdirectory-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAliasT%2Fdirectory-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a40ead72a1733ed4434b535bba62e196defb55d1
[INFO] documenting AliasT/directory-tree against 1.91.0 for beta-1.92-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAliasT%2Fdirectory-tree" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/AliasT/directory-tree
[INFO] finished tweaking git repo https://github.com/AliasT/directory-tree
[INFO] tweaked toml for git repo https://github.com/AliasT/directory-tree written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/AliasT/directory-tree 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] crate git repo https://github.com/AliasT/directory-tree 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" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded neon-runtime v0.8.2
[INFO] [stderr]   Downloaded cslice v0.2.0
[INFO] [stderr]   Downloaded neon-build v0.8.2
[INFO] [stderr]   Downloaded neon-macros v0.8.2
[INFO] [stderr]   Downloaded neon v0.8.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 191f17097daeb8af0a5696f8120a0e6bdd513c60a64c1154a4f8841f556c1bc9
[INFO] running `Command { std: "docker" "start" "-a" "191f17097daeb8af0a5696f8120a0e6bdd513c60a64c1154a4f8841f556c1bc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "191f17097daeb8af0a5696f8120a0e6bdd513c60a64c1154a4f8841f556c1bc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "191f17097daeb8af0a5696f8120a0e6bdd513c60a64c1154a4f8841f556c1bc9", kill_on_drop: false }`
[INFO] [stdout] 191f17097daeb8af0a5696f8120a0e6bdd513c60a64c1154a4f8841f556c1bc9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e5936770e19b74f3861663cb271cce2f8cea3e78b65aaf2f7eb9e086c80792c4
[INFO] running `Command { std: "docker" "start" "-a" "e5936770e19b74f3861663cb271cce2f8cea3e78b65aaf2f7eb9e086c80792c4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling neon-build v0.8.2
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]     Checking cslice v0.2.0
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking libloading v0.6.7
[INFO] [stderr]     Checking neon-runtime v0.8.2
[INFO] [stderr]    Compiling neon v0.8.2
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling neon-macros v0.8.2
[INFO] [stderr]  Documenting directory-tree v0.0.1 (/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(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `directory-tree`
[INFO] running `Command { std: "docker" "inspect" "e5936770e19b74f3861663cb271cce2f8cea3e78b65aaf2f7eb9e086c80792c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e5936770e19b74f3861663cb271cce2f8cea3e78b65aaf2f7eb9e086c80792c4", kill_on_drop: false }`
[INFO] [stdout] e5936770e19b74f3861663cb271cce2f8cea3e78b65aaf2f7eb9e086c80792c4
