[INFO] fetching crate tiered-result 0.1.0...
[INFO] documenting tiered-result-0.1.0 against 1.76.0 for beta-1.77-rustdoc-1
[INFO] extracting crate tiered-result 0.1.0 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate tiered-result 0.1.0 on toolchain 1.76.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate tiered-result 0.1.0
[INFO] finished tweaking crates.io crate tiered-result 0.1.0
[INFO] tweaked toml for crates.io crate tiered-result 0.1.0 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded nullable-result v0.7.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+1.76.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9b694f04557accc0a14b8a2a7015e6fa709c19c05e124d8371f44e2acf99bd98
[INFO] running `Command { std: "docker" "start" "-a" "9b694f04557accc0a14b8a2a7015e6fa709c19c05e124d8371f44e2acf99bd98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9b694f04557accc0a14b8a2a7015e6fa709c19c05e124d8371f44e2acf99bd98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9b694f04557accc0a14b8a2a7015e6fa709c19c05e124d8371f44e2acf99bd98", kill_on_drop: false }`
[INFO] [stdout] 9b694f04557accc0a14b8a2a7015e6fa709c19c05e124d8371f44e2acf99bd98
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+1.76.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2a9626bdf4acc36d3d84e60129b0971cac47a311a6aa4f31cbd034c851b1f795
[INFO] running `Command { std: "docker" "start" "-a" "2a9626bdf4acc36d3d84e60129b0971cac47a311a6aa4f31cbd034c851b1f795", kill_on_drop: false }`
[INFO] [stderr]     Checking nullable-result v0.7.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/nullable-result-0.7.0/src/lib.rs:11:44
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![cfg_attr(feature = "try_trait", feature(try_trait_v2))]
[INFO] [stdout]    |                                            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `nullable-result` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "2a9626bdf4acc36d3d84e60129b0971cac47a311a6aa4f31cbd034c851b1f795", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a9626bdf4acc36d3d84e60129b0971cac47a311a6aa4f31cbd034c851b1f795", kill_on_drop: false }`
[INFO] [stdout] 2a9626bdf4acc36d3d84e60129b0971cac47a311a6aa4f31cbd034c851b1f795
