[INFO] cloning repository https://github.com/martin-t/sokoban-solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/martin-t/sokoban-solver" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmartin-t%2Fsokoban-solver", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmartin-t%2Fsokoban-solver'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 11288f2d04bcea7b1a42927df7e031488fb7c525
[INFO] documenting martin-t/sokoban-solver against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmartin-t%2Fsokoban-solver" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/martin-t/sokoban-solver on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/martin-t/sokoban-solver
[INFO] finished tweaking git repo https://github.com/martin-t/sokoban-solver
[INFO] tweaked toml for git repo https://github.com/martin-t/sokoban-solver written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/martin-t/sokoban-solver already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded criterion-plot v0.4.1
[INFO] [stderr]   Downloaded criterion v0.3.1
[INFO] [stderr]   Downloaded predicates v1.0.4
[INFO] [stderr]   Downloaded escargot v0.5.0
[INFO] [stderr]   Downloaded oorandom v11.1.0
[INFO] [stderr]   Downloaded plotters v0.2.12
[INFO] [stderr]   Downloaded assert_cmd v1.0.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 04cf9ad9ae290b0506a32104a724557711257f78f2cd7a2aa3065cc86b2cfd18
[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" "04cf9ad9ae290b0506a32104a724557711257f78f2cd7a2aa3065cc86b2cfd18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "04cf9ad9ae290b0506a32104a724557711257f78f2cd7a2aa3065cc86b2cfd18", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04cf9ad9ae290b0506a32104a724557711257f78f2cd7a2aa3065cc86b2cfd18", kill_on_drop: false }`
[INFO] [stdout] 04cf9ad9ae290b0506a32104a724557711257f78f2cd7a2aa3065cc86b2cfd18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1b6a6536dd68645087c36d9db47f35de3205b95214b2b22b36a484dde52f1ef5
[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" "1b6a6536dd68645087c36d9db47f35de3205b95214b2b22b36a484dde52f1ef5", kill_on_drop: false }`
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]     Checking quick-error v1.2.3
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking termcolor v1.1.0
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking typed-arena v2.0.1
[INFO] [stderr]     Checking separator v0.4.1
[INFO] [stderr]     Checking fnv v1.0.6
[INFO] [stderr]     Checking libc v0.2.68
[INFO] [stderr]     Checking memchr v2.3.3
[INFO] [stderr]     Checking bitflags v1.2.1
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking aho-corasick v0.7.10
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking regex v1.3.6
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]  Documenting sokoban-solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(crate_visibility_modifier)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(min_specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(stmt_expr_attributes)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 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 `sokoban-solver`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name sokoban_solver 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 clap=/opt/rustwide/target/debug/deps/libclap-464c6973b2857366.rmeta --extern env_logger=/opt/rustwide/target/debug/deps/libenv_logger-fa15546365343587.rmeta --extern fnv=/opt/rustwide/target/debug/deps/libfnv-fd268ae3e9f326d2.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-3bb51d73f2016ec6.rmeta --extern separator=/opt/rustwide/target/debug/deps/libseparator-9720abcba09f12e5.rmeta --extern typed_arena=/opt/rustwide/target/debug/deps/libtyped_arena-5b4cb2a9fb0a9dcc.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "1b6a6536dd68645087c36d9db47f35de3205b95214b2b22b36a484dde52f1ef5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b6a6536dd68645087c36d9db47f35de3205b95214b2b22b36a484dde52f1ef5", kill_on_drop: false }`
[INFO] [stdout] 1b6a6536dd68645087c36d9db47f35de3205b95214b2b22b36a484dde52f1ef5