[INFO] cloning repository https://github.com/knapply/pygrex
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/knapply/pygrex" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fknapply%2Fpygrex", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fknapply%2Fpygrex'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a59a03805a26d53ce98088c5edb6533b24512bf7
[INFO] documenting knapply/pygrex 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%2Fknapply%2Fpygrex" "/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/knapply/pygrex 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] removed /workspace/builds/worker-0/source/.cargo/config
[INFO] started tweaking git repo https://github.com/knapply/pygrex
[INFO] finished tweaking git repo https://github.com/knapply/pygrex
[INFO] tweaked toml for git repo https://github.com/knapply/pygrex written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/knapply/pygrex 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]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_json v1.0.52
[INFO] [stderr]   Downloaded unic-common v0.9.0
[INFO] [stderr]   Downloaded grex v1.1.0
[INFO] [stderr]   Downloaded fixedbitset v0.2.0
[INFO] [stderr]   Downloaded unic-char-range v0.9.0
[INFO] [stderr]   Downloaded unindent v0.1.5
[INFO] [stderr]   Downloaded unic-ucd-category v0.9.0
[INFO] [stderr]   Downloaded indoc v0.3.5
[INFO] [stderr]   Downloaded petgraph v0.5.0
[INFO] [stderr]   Downloaded unic-char-property v0.9.0
[INFO] [stderr]   Downloaded syn v1.0.18
[INFO] [stderr]   Downloaded pyo3cls v0.9.2
[INFO] [stderr]   Downloaded pyo3-derive-backend v0.9.2
[INFO] [stderr]   Downloaded paste-impl v0.1.11
[INFO] [stderr]   Downloaded indoc-impl v0.3.5
[INFO] [stderr]   Downloaded pyo3 v0.9.2
[INFO] [stderr]   Downloaded regex v1.3.7
[INFO] [stderr]   Downloaded hermit-abi v0.1.12
[INFO] [stderr]   Downloaded libc v0.2.69
[INFO] [stderr]   Downloaded ndarray v0.13.1
[INFO] [stderr]   Downloaded unic-ucd-version v0.9.0
[INFO] [stderr]   Downloaded paste v0.1.11
[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] 448761ad160748dfc81d49b317afe565bbaf76faf327c78d0db92a74b6fb7496
[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" "448761ad160748dfc81d49b317afe565bbaf76faf327c78d0db92a74b6fb7496", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "448761ad160748dfc81d49b317afe565bbaf76faf327c78d0db92a74b6fb7496", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "448761ad160748dfc81d49b317afe565bbaf76faf327c78d0db92a74b6fb7496", kill_on_drop: false }`
[INFO] [stdout] 448761ad160748dfc81d49b317afe565bbaf76faf327c78d0db92a74b6fb7496
[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] 5b554f2dcaafc3a93042e2bac382daea5d03e26e261513469b30418d65f85cf4
[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" "5b554f2dcaafc3a93042e2bac382daea5d03e26e261513469b30418d65f85cf4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]    Compiling itoa v0.4.5
[INFO] [stderr]    Compiling regex-syntax v0.6.17
[INFO] [stderr]    Compiling ndarray v0.13.1
[INFO] [stderr]    Compiling unindent v0.1.5
[INFO] [stderr]     Checking fixedbitset v0.2.0
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]    Compiling ryu v1.0.4
[INFO] [stderr]     Checking unic-ucd-category v0.9.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking parking_lot_core v0.7.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/lock_api-0.3.4/src/lib.rs:91:34
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking colored v1.9.3
[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 compile `lock_api`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "5b554f2dcaafc3a93042e2bac382daea5d03e26e261513469b30418d65f85cf4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b554f2dcaafc3a93042e2bac382daea5d03e26e261513469b30418d65f85cf4", kill_on_drop: false }`
[INFO] [stdout] 5b554f2dcaafc3a93042e2bac382daea5d03e26e261513469b30418d65f85cf4