[INFO] fetching crate biostats 0.2.2...
[INFO] documenting biostats-0.2.2 against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] extracting crate biostats 0.2.2 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate biostats 0.2.2 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 crates.io crate biostats 0.2.2
[INFO] finished tweaking crates.io crate biostats 0.2.2
[INFO] tweaked toml for crates.io crate biostats 0.2.2 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate biostats 0.2.2 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 program-flow v0.1.3
[INFO] [stderr]   Downloaded math v0.8.5
[INFO] [stderr]   Downloaded biofile v1.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 01703ea8d0287d02b865087cf3ca79ddb7fce99a840073022e423f40219873d3
[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" "01703ea8d0287d02b865087cf3ca79ddb7fce99a840073022e423f40219873d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "01703ea8d0287d02b865087cf3ca79ddb7fce99a840073022e423f40219873d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "01703ea8d0287d02b865087cf3ca79ddb7fce99a840073022e423f40219873d3", kill_on_drop: false }`
[INFO] [stdout] 01703ea8d0287d02b865087cf3ca79ddb7fce99a840073022e423f40219873d3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 08a8a39e8a57882073fa0c6ae7f39f56b53ea764000391d7c61559167cf6a96f
[INFO] running `Command { std: "docker" "start" "-a" "08a8a39e8a57882073fa0c6ae7f39f56b53ea764000391d7c61559167cf6a96f", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling ndarray v0.12.1
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling memoffset v0.5.5
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]     Checking itertools v0.7.11
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking clap v2.33.1
[INFO] [stderr]     Checking crossbeam-queue v0.2.3
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking rayon-core v1.7.1
[INFO] [stderr]     Checking rayon v1.3.1
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]     Checking program-flow v0.1.3
[INFO] [stderr]     Checking math v0.8.5
[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/math-0.8.5/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/math-0.8.5/src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(bool_to_option)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[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] [stderr] error: could not compile `math`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "08a8a39e8a57882073fa0c6ae7f39f56b53ea764000391d7c61559167cf6a96f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08a8a39e8a57882073fa0c6ae7f39f56b53ea764000391d7c61559167cf6a96f", kill_on_drop: false }`
[INFO] [stdout] 08a8a39e8a57882073fa0c6ae7f39f56b53ea764000391d7c61559167cf6a96f