[INFO] cloning repository https://github.com/123dou/learnRust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/123dou/learnRust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F123dou%2FlearnRust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F123dou%2FlearnRust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f9b44b36f613944d8f197a85cadff7b5da58f239
[INFO] documenting 123dou/learnRust against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F123dou%2FlearnRust" "/workspace/builds/worker-31/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-31/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/123dou/learnRust on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/123dou/learnRust
[INFO] finished tweaking git repo https://github.com/123dou/learnRust
[INFO] tweaked toml for git repo https://github.com/123dou/learnRust written to /workspace/builds/worker-31/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "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" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: profile `doc` is deprecated and has no effect
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-31/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-31/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0d2684b5f7fbcc4e3c4b4b8591071f1504a50be463705d59aeec9396e00c5958
[INFO] running `Command { std: "docker" "start" "-a" "0d2684b5f7fbcc4e3c4b4b8591071f1504a50be463705d59aeec9396e00c5958", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d2684b5f7fbcc4e3c4b4b8591071f1504a50be463705d59aeec9396e00c5958", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d2684b5f7fbcc4e3c4b4b8591071f1504a50be463705d59aeec9396e00c5958", kill_on_drop: false }`
[INFO] [stdout] 0d2684b5f7fbcc4e3c4b4b8591071f1504a50be463705d59aeec9396e00c5958
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-31/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-31/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:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f4c03684da5d7d88ec3a73c12bd2d882743b2fc0625655504644b16276b22e10
[INFO] running `Command { std: "docker" "start" "-a" "f4c03684da5d7d88ec3a73c12bd2d882743b2fc0625655504644b16276b22e10", kill_on_drop: false }`
[INFO] [stderr] warning: profile `doc` is deprecated and has no effect
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.0
[INFO] [stderr]    Compiling syn v1.0.95
[INFO] [stderr]    Compiling serde_derive v1.0.137
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]     Checking ryu v1.0.10
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking itertools v0.9.0
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking toml v0.5.9
[INFO] [stderr]  Documenting learn_rust 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:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(drain_filter)]
[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:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(entry_insert)]
[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:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(binary_heap_into_iter_sorted)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `learn_rust`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name learn_rust src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=eb58e01aefd2ede0 -L dependency=/opt/rustwide/target/debug/deps --extern itertools=/opt/rustwide/target/debug/deps/libitertools-79271da6eb8d3b12.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-741529f644924c90.rmeta --extern crypto=/opt/rustwide/target/debug/deps/libcrypto-4d0a4eee4384f8ad.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-f4711f4b5289cb3a.rmeta --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-5213a8074e79320d.rmeta --extern toml=/opt/rustwide/target/debug/deps/libtoml-c9d93ba8c39abb64.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "f4c03684da5d7d88ec3a73c12bd2d882743b2fc0625655504644b16276b22e10", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f4c03684da5d7d88ec3a73c12bd2d882743b2fc0625655504644b16276b22e10", kill_on_drop: false }`
[INFO] [stdout] f4c03684da5d7d88ec3a73c12bd2d882743b2fc0625655504644b16276b22e10