[INFO] fetching crate mech-wasm 0.0.5...
[INFO] documenting mech-wasm-0.0.5 against 1.54.0 for beta-1.55-rustdoc-1
[INFO] extracting crate mech-wasm 0.0.5 into /workspace/builds/worker-96/source
[INFO] validating manifest of crates.io crate mech-wasm 0.0.5 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mech-wasm 0.0.5
[INFO] finished tweaking crates.io crate mech-wasm 0.0.5
[INFO] tweaked toml for crates.io crate mech-wasm 0.0.5 written to /workspace/builds/worker-96/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded mech-math v0.0.5
[INFO] [stderr]   Downloaded mech-syntax v0.0.5
[INFO] [stderr]   Downloaded mech-core v0.0.5
[INFO] [stderr]   Downloaded mech-utilities v0.0.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-96/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-96/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a91fdbaaae6b0d8779b9e4aec0cb9d2777e18ca972f8632e39ec9fc2b20b8d03
[INFO] running `Command { std: "docker" "start" "-a" "a91fdbaaae6b0d8779b9e4aec0cb9d2777e18ca972f8632e39ec9fc2b20b8d03", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a91fdbaaae6b0d8779b9e4aec0cb9d2777e18ca972f8632e39ec9fc2b20b8d03", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a91fdbaaae6b0d8779b9e4aec0cb9d2777e18ca972f8632e39ec9fc2b20b8d03", kill_on_drop: false }`
[INFO] [stdout] a91fdbaaae6b0d8779b9e4aec0cb9d2777e18ca972f8632e39ec9fc2b20b8d03
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-96/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-96/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fdbc57471f74f0820012c20512782f9f5d2befaeea54719bc4c7cc9eb1fdb180
[INFO] running `Command { std: "docker" "start" "-a" "fdbc57471f74f0820012c20512782f9f5d2befaeea54719bc4c7cc9eb1fdb180", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.75
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling bumpalo v3.7.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]     Checking ahash v0.3.8
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling lexical-core v0.7.6
[INFO] [stderr]    Compiling wasm-bindgen v0.2.75
[INFO] [stderr]     Checking arrayvec v0.5.2
[INFO] [stderr]    Compiling libm v0.1.4
[INFO] [stderr]     Checking static_assertions v1.1.0
[INFO] [stderr]    Compiling hashbrown v0.7.2
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling log v0.4.14
[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/hashbrown-0.7.2/src/lib.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     feature(
[INFO] [stdout] 16 | |         alloc_layout_extra,
[INFO] [stdout] 17 | |         allocator_api,
[INFO] [stdout] 18 | |         ptr_offset_from,
[INFO] [stdout] ...  |
[INFO] [stdout] 22 | |         specialization,
[INFO] [stdout] 23 | |     )
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hashbrown`
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[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" "fdbc57471f74f0820012c20512782f9f5d2befaeea54719bc4c7cc9eb1fdb180", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fdbc57471f74f0820012c20512782f9f5d2befaeea54719bc4c7cc9eb1fdb180", kill_on_drop: false }`
[INFO] [stdout] fdbc57471f74f0820012c20512782f9f5d2befaeea54719bc4c7cc9eb1fdb180
