[INFO] fetching crate modus_ponens_derive 0.1.0...
[INFO] documenting modus_ponens_derive-0.1.0 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate modus_ponens_derive 0.1.0 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate modus_ponens_derive 0.1.0 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 modus_ponens_derive 0.1.0
[INFO] finished tweaking crates.io crate modus_ponens_derive 0.1.0
[INFO] tweaked toml for crates.io crate modus_ponens_derive 0.1.0 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] 70e139738d414ce6d6aa1d58a59a301549bf716bfb87e6c553fe929a294c9f75
[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" "70e139738d414ce6d6aa1d58a59a301549bf716bfb87e6c553fe929a294c9f75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "70e139738d414ce6d6aa1d58a59a301549bf716bfb87e6c553fe929a294c9f75", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "70e139738d414ce6d6aa1d58a59a301549bf716bfb87e6c553fe929a294c9f75", kill_on_drop: false }`
[INFO] [stdout] 70e139738d414ce6d6aa1d58a59a301549bf716bfb87e6c553fe929a294c9f75
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] e59324337f134a4c8806894823bb9305cecc2947fc22b86bb41c5ae859d65938
[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" "e59324337f134a4c8806894823bb9305cecc2947fc22b86bb41c5ae859d65938", kill_on_drop: false }`
[INFO] [stderr]     Checking bumpalo v3.4.0
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]     Checking syn v1.0.39
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]     Checking modus_ponens v0.11.2
[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/modus_ponens-0.11.2/src/lib.rs:20:1
[INFO] [stdout]    |
[INFO] [stdout] 20 | #![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 `modus_ponens`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "e59324337f134a4c8806894823bb9305cecc2947fc22b86bb41c5ae859d65938", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e59324337f134a4c8806894823bb9305cecc2947fc22b86bb41c5ae859d65938", kill_on_drop: false }`
[INFO] [stdout] e59324337f134a4c8806894823bb9305cecc2947fc22b86bb41c5ae859d65938