[INFO] fetching crate cargo-modules 0.4.9...
[INFO] documenting cargo-modules-0.4.9 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate cargo-modules 0.4.9 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate cargo-modules 0.4.9 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 crates.io crate cargo-modules 0.4.9
[INFO] finished tweaking crates.io crate cargo-modules 0.4.9
[INFO] tweaked toml for crates.io crate cargo-modules 0.4.9 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate cargo-modules 0.4.9 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]     Blocking waiting for file lock on package cache
[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" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b8642c01cdb47f4b0cba2a2032658aa2e538ba8692267d43a7ea7b3b4ef3c82d
[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" "b8642c01cdb47f4b0cba2a2032658aa2e538ba8692267d43a7ea7b3b4ef3c82d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b8642c01cdb47f4b0cba2a2032658aa2e538ba8692267d43a7ea7b3b4ef3c82d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8642c01cdb47f4b0cba2a2032658aa2e538ba8692267d43a7ea7b3b4ef3c82d", kill_on_drop: false }`
[INFO] [stdout] b8642c01cdb47f4b0cba2a2032658aa2e538ba8692267d43a7ea7b3b4ef3c82d
[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" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c0f9a26e2361803c77ab02aa725cfaae901923ddf532d5bbcb802f648339a899
[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" "c0f9a26e2361803c77ab02aa725cfaae901923ddf532d5bbcb802f648339a899", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.70
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.13
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.22
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]     Checking smallvec v1.4.0
[INFO] [stderr]    Compiling cc v1.0.54
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling rustc-rayon-core v0.3.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.0/lib.rs:61:32
[INFO] [stdout]    |
[INFO] [stdout] 61 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.0/lib.rs:63:37
[INFO] [stdout]    |
[INFO] [stdout] 63 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking byte-tools v0.3.1
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smallvec`.
[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" "c0f9a26e2361803c77ab02aa725cfaae901923ddf532d5bbcb802f648339a899", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c0f9a26e2361803c77ab02aa725cfaae901923ddf532d5bbcb802f648339a899", kill_on_drop: false }`
[INFO] [stdout] c0f9a26e2361803c77ab02aa725cfaae901923ddf532d5bbcb802f648339a899