[INFO] cloning repository https://github.com/cmourglia/chess_engine
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cmourglia/chess_engine" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmourglia%2Fchess_engine", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcmourglia%2Fchess_engine'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d86f65ada4624fdcacdc1300cb4235a371024829
[INFO] documenting cmourglia/chess_engine 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%2Fcmourglia%2Fchess_engine" "/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/cmourglia/chess_engine 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/cmourglia/chess_engine
[INFO] finished tweaking git repo https://github.com/cmourglia/chess_engine
[INFO] tweaked toml for git repo https://github.com/cmourglia/chess_engine written to /workspace/builds/worker-31/source/Cargo.toml
[INFO] crate git repo https://github.com/cmourglia/chess_engine already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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] c1f698d1429d53e36e01bb161dc8bcf4c99396e2f31923a860be58a8d5589214
[INFO] running `Command { std: "docker" "start" "-a" "c1f698d1429d53e36e01bb161dc8bcf4c99396e2f31923a860be58a8d5589214", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c1f698d1429d53e36e01bb161dc8bcf4c99396e2f31923a860be58a8d5589214", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c1f698d1429d53e36e01bb161dc8bcf4c99396e2f31923a860be58a8d5589214", kill_on_drop: false }`
[INFO] [stdout] c1f698d1429d53e36e01bb161dc8bcf4c99396e2f31923a860be58a8d5589214
[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] bee01965d3b7760fc4b128d89bee22db13e5afbb018d1780c2cb23253afb4e71
[INFO] running `Command { std: "docker" "start" "-a" "bee01965d3b7760fc4b128d89bee22db13e5afbb018d1780c2cb23253afb4e71", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling libc v0.2.116
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling ppv-lite86 v0.2.16
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling siphasher v0.3.9
[INFO] [stderr]     Checking phf_shared v0.10.0
[INFO] [stderr]    Compiling quote v1.0.15
[INFO] [stderr]    Compiling getrandom v0.2.4
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling phf_generator v0.10.0
[INFO] [stderr]    Compiling toml v0.5.8
[INFO] [stderr]    Compiling thiserror-impl v1.0.30
[INFO] [stderr]    Compiling phf_macros v0.10.0
[INFO] [stderr]     Checking phf v0.10.1
[INFO] [stderr]    Compiling thiserror v1.0.30
[INFO] [stderr]    Compiling proc-macro-crate v1.1.0
[INFO] [stderr]    Compiling num_enum_derive v0.5.6
[INFO] [stderr]     Checking num_enum v0.5.6
[INFO] [stderr]  Documenting chess_engine v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(variant_count)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `chess_engine`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2021 --crate-type bin --crate-name chess_engine src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=bc1168ee67d04893 -L dependency=/opt/rustwide/target/debug/deps --extern num_enum=/opt/rustwide/target/debug/deps/libnum_enum-05cc343d0a2897db.rmeta --extern phf=/opt/rustwide/target/debug/deps/libphf-c5a2cea304990b7c.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "bee01965d3b7760fc4b128d89bee22db13e5afbb018d1780c2cb23253afb4e71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bee01965d3b7760fc4b128d89bee22db13e5afbb018d1780c2cb23253afb4e71", kill_on_drop: false }`
[INFO] [stdout] bee01965d3b7760fc4b128d89bee22db13e5afbb018d1780c2cb23253afb4e71