[INFO] cloning repository https://github.com/kstrohbeck/picross-solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kstrohbeck/picross-solver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkstrohbeck%2Fpicross-solver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkstrohbeck%2Fpicross-solver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8f538c9a0565d817c8963e8ccebb15bdc8162841
[INFO] documenting kstrohbeck/picross-solver against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkstrohbeck%2Fpicross-solver" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kstrohbeck/picross-solver on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kstrohbeck/picross-solver
[INFO] finished tweaking git repo https://github.com/kstrohbeck/picross-solver
[INFO] tweaked toml for git repo https://github.com/kstrohbeck/picross-solver written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/kstrohbeck/picross-solver already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: the cargo feature `edition` is now stable and is no longer necessary to be listed in the manifest
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] b203eec5ac654c1808327f514c1813506e54fc705fe207721600afe10366f0b0
[INFO] running `Command { std: "docker" "start" "-a" "b203eec5ac654c1808327f514c1813506e54fc705fe207721600afe10366f0b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b203eec5ac654c1808327f514c1813506e54fc705fe207721600afe10366f0b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b203eec5ac654c1808327f514c1813506e54fc705fe207721600afe10366f0b0", kill_on_drop: false }`
[INFO] [stdout] b203eec5ac654c1808327f514c1813506e54fc705fe207721600afe10366f0b0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 515616dc7f1d6fb74acae6040869fa82413cdcc9686e9367778090c97ba24ace
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "515616dc7f1d6fb74acae6040869fa82413cdcc9686e9367778090c97ba24ace", kill_on_drop: false }`
[INFO] [stderr] warning: the cargo feature `edition` is now stable and is no longer necessary to be listed in the manifest
[INFO] [stderr]    Compiling proc-macro2 v0.4.13
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling serde v1.0.75
[INFO] [stderr]    Compiling ryu v0.2.6
[INFO] [stderr]     Checking itoa v0.4.2
[INFO] [stderr]     Checking either v1.5.0
[INFO] [stderr]     Checking streaming-iterator v0.1.4
[INFO] [stderr]     Checking itertools v0.7.8
[INFO] [stderr]    Compiling quote v0.6.8
[INFO] [stderr]    Compiling syn v0.14.9
[INFO] [stderr]    Compiling serde_derive v1.0.75
[INFO] [stderr]     Checking serde_json v1.0.26
[INFO] [stderr]     Checking picross-solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting picross-solver 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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(uniform_paths)]
[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] [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(uniform_paths)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `picross-solver`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name picross_lib 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 itertools=/opt/rustwide/target/debug/deps/libitertools-a4e01d700bacbbb2.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-5ce26244de0b22d6.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-c1378ba392515d67.so --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-ba94ac13adf59d52.rmeta --extern streaming_iterator=/opt/rustwide/target/debug/deps/libstreaming_iterator-d1c976284ca44543.rmeta --cap-lints=warn` (exit code: 1)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0599]: no method named `step_as_child` found for mutable reference `&mut puzzle::Puzzle` in the current scope
[INFO] [stdout]   --> src/puzzle.rs:98:30
[INFO] [stdout]    |
[INFO] [stdout] 98 |         while let res = self.step_as_child() {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^ help: there is an associated function with a similar name: `solve_as_child`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> src/puzzle.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |       pub fn solve_as_child(&mut self) -> Option<bool> {
[INFO] [stdout]    |                                           ------------ expected `std::option::Option<bool>` because of return type
[INFO] [stdout] 98 | /         while let res = self.step_as_child() {
[INFO] [stdout] 99 | |         }
[INFO] [stdout]    | |_________^ expected enum `std::option::Option`, found `()`
[INFO] [stdout]    |
[INFO] [stdout]    = note:   expected enum `std::option::Option<bool>`
[INFO] [stdout]            found unit type `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0308, E0554, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "515616dc7f1d6fb74acae6040869fa82413cdcc9686e9367778090c97ba24ace", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "515616dc7f1d6fb74acae6040869fa82413cdcc9686e9367778090c97ba24ace", kill_on_drop: false }`
[INFO] [stdout] 515616dc7f1d6fb74acae6040869fa82413cdcc9686e9367778090c97ba24ace