[INFO] fetching crate boomerang 0.1.0...
[INFO] documenting boomerang-0.1.0 against 1.47.0 for beta-1.48-rustdoc-1
[INFO] extracting crate boomerang 0.1.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate boomerang 0.1.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate boomerang 0.1.0
[INFO] finished tweaking crates.io crate boomerang 0.1.0
[INFO] tweaked toml for crates.io crate boomerang 0.1.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+1.47.0" "metadata" "--no-deps" "--format-version=1", 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] 773031a961617f8f8d47bfed20058d02ee6675d3e54747a470d09dd9d3912d39
[INFO] running `Command { std: "docker" "start" "-a" "773031a961617f8f8d47bfed20058d02ee6675d3e54747a470d09dd9d3912d39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "773031a961617f8f8d47bfed20058d02ee6675d3e54747a470d09dd9d3912d39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "773031a961617f8f8d47bfed20058d02ee6675d3e54747a470d09dd9d3912d39", kill_on_drop: false }`
[INFO] [stdout] 773031a961617f8f8d47bfed20058d02ee6675d3e54747a470d09dd9d3912d39
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+1.47.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] eb6baa1bf0706bf01fc250cc299483110e3969b7303fe46cdf58b2e7ad7e414a
[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" "eb6baa1bf0706bf01fc250cc299483110e3969b7303fe46cdf58b2e7ad7e414a", kill_on_drop: false }`
[INFO] [stderr]    Compiling strsim v0.9.3
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling syn v1.0.45
[INFO] [stderr]     Checking tabular v0.1.4
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling petgraph v0.5.1
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling parse_duration v2.1.0
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling boomerang_derive v0.1.0
[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/boomerang_derive-0.1.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(hash_set_entry)]
[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 compile `boomerang_derive`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "eb6baa1bf0706bf01fc250cc299483110e3969b7303fe46cdf58b2e7ad7e414a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eb6baa1bf0706bf01fc250cc299483110e3969b7303fe46cdf58b2e7ad7e414a", kill_on_drop: false }`
[INFO] [stdout] eb6baa1bf0706bf01fc250cc299483110e3969b7303fe46cdf58b2e7ad7e414a
