[INFO] fetching crate mamba 0.3.0...
[INFO] documenting mamba-0.3.0 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate mamba 0.3.0 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate mamba 0.3.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mamba 0.3.0
[INFO] finished tweaking crates.io crate mamba 0.3.0
[INFO] tweaked toml for crates.io crate mamba 0.3.0 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate crates.io crate mamba 0.3.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 22c71d6b39fa0318ab9f254c825e210bf5915b3b7f9b750e4483f7925e05ebfc
[INFO] running `Command { std: "docker" "start" "-a" "22c71d6b39fa0318ab9f254c825e210bf5915b3b7f9b750e4483f7925e05ebfc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "22c71d6b39fa0318ab9f254c825e210bf5915b3b7f9b750e4483f7925e05ebfc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22c71d6b39fa0318ab9f254c825e210bf5915b3b7f9b750e4483f7925e05ebfc", kill_on_drop: false }`
[INFO] [stdout] 22c71d6b39fa0318ab9f254c825e210bf5915b3b7f9b750e4483f7925e05ebfc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 131f73657e1bbaf16a40dbd15e6ba14513d15498ea9280d5b35ba9eb66965671
[INFO] running `Command { std: "docker" "start" "-a" "131f73657e1bbaf16a40dbd15e6ba14513d15498ea9280d5b35ba9eb66965671", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling escargot v0.3.1
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking wtf8 v0.0.3
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking unicode_names2 v0.2.2
[INFO] [stderr]     Checking pathdiff v0.1.0
[INFO] [stderr]    Compiling num-traits v0.2.10
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-bigint v0.2.4
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]     Checking itertools v0.8.2
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking predicates v1.0.2
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking nom_locate v0.3.1
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking loggerv v0.7.2
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking python-parser v0.1.0
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]     Checking serde_json v1.0.44
[INFO] [stderr]     Checking assert_cmd v0.10.2
[INFO] [stderr]  Documenting mamba v0.3.0 (/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(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `mamba`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name mamba src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern ansi_term=/opt/rustwide/target/debug/deps/libansi_term-fd7abddf7181542f.rmeta --extern assert_cmd=/opt/rustwide/target/debug/deps/libassert_cmd-921a381840093d94.rmeta --extern clap=/opt/rustwide/target/debug/deps/libclap-ffa41f6e9e4e132c.rmeta --extern glob=/opt/rustwide/target/debug/deps/libglob-dd005bda8a71734d.rmeta --extern itertools=/opt/rustwide/target/debug/deps/libitertools-8965a3d9bbcd50d2.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-3350f96749421cbd.rmeta --extern loggerv=/opt/rustwide/target/debug/deps/libloggerv-9f52d5fd0c6c2221.rmeta --extern pathdiff=/opt/rustwide/target/debug/deps/libpathdiff-e1fd8dc99019f84e.rmeta --extern python_parser=/opt/rustwide/target/debug/deps/libpython_parser-0fc4fdafad457357.rmeta --extern tempfile=/opt/rustwide/target/debug/deps/libtempfile-57763fd6b2106820.rmeta --cap-lints=warn --crate-version 0.3.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "131f73657e1bbaf16a40dbd15e6ba14513d15498ea9280d5b35ba9eb66965671", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "131f73657e1bbaf16a40dbd15e6ba14513d15498ea9280d5b35ba9eb66965671", kill_on_drop: false }`
[INFO] [stdout] 131f73657e1bbaf16a40dbd15e6ba14513d15498ea9280d5b35ba9eb66965671
