[INFO] fetching crate givable_mutex 0.3.0...
[INFO] documenting givable_mutex-0.3.0 against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] extracting crate givable_mutex 0.3.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate givable_mutex 0.3.0 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate givable_mutex 0.3.0
[INFO] finished tweaking crates.io crate givable_mutex 0.3.0
[INFO] tweaked toml for crates.io crate givable_mutex 0.3.0 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7f5ae4c3a680d5aa5dd35630583dbbfabd2abc2045d3e92333df8b7ee1915ad6
[INFO] running `Command { std: "docker" "start" "-a" "7f5ae4c3a680d5aa5dd35630583dbbfabd2abc2045d3e92333df8b7ee1915ad6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7f5ae4c3a680d5aa5dd35630583dbbfabd2abc2045d3e92333df8b7ee1915ad6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7f5ae4c3a680d5aa5dd35630583dbbfabd2abc2045d3e92333df8b7ee1915ad6", kill_on_drop: false }`
[INFO] [stdout] 7f5ae4c3a680d5aa5dd35630583dbbfabd2abc2045d3e92333df8b7ee1915ad6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] afc722ff96f5fdcce185808bc321da0b18dfe9d2ff03dafba1a442b48d4ffca8
[INFO] running `Command { std: "docker" "start" "-a" "afc722ff96f5fdcce185808bc321da0b18dfe9d2ff03dafba1a442b48d4ffca8", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking thread_local v1.1.3
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]  Documenting givable_mutex v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:42
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]   |                                          ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:34
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]   |                                  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `givable_mutex`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name givable_mutex src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --cfg 'feature="nightly"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern lock_api=/opt/rustwide/target/debug/deps/liblock_api-38906a12aa57830d.rmeta --extern once_cell=/opt/rustwide/target/debug/deps/libonce_cell-f0af484c73954b52.rmeta --extern parking_lot=/opt/rustwide/target/debug/deps/libparking_lot-a5e1a9dc3a44a839.rmeta --extern thread_local=/opt/rustwide/target/debug/deps/libthread_local-678ab989d6d66242.rmeta --cap-lints=warn --crate-version 0.3.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "afc722ff96f5fdcce185808bc321da0b18dfe9d2ff03dafba1a442b48d4ffca8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "afc722ff96f5fdcce185808bc321da0b18dfe9d2ff03dafba1a442b48d4ffca8", kill_on_drop: false }`
[INFO] [stdout] afc722ff96f5fdcce185808bc321da0b18dfe9d2ff03dafba1a442b48d4ffca8
