[INFO] crate restruct_derive 0.1.0 is already in cache
[INFO] testing restruct_derive-0.1.0 against 1.44.0 for beta-1.45-1
[INFO] extracting crate restruct_derive 0.1.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate restruct_derive 0.1.0 on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate restruct_derive 0.1.0
[INFO] finished tweaking crates.io crate restruct_derive 0.1.0
[INFO] tweaked toml for crates.io crate restruct_derive 0.1.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] a9ed40510443208ef462acf7c19a6ebc56e36221485a3b68e1ac346e697e3da8
[INFO] running `"docker" "start" "-a" "a9ed40510443208ef462acf7c19a6ebc56e36221485a3b68e1ac346e697e3da8"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling syn v1.0.30
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling pest_meta v2.1.3
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]    Compiling restruct v0.1.0
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/restruct-0.1.0/src/lib.rs:31:1
[INFO] [stderr]    |
[INFO] [stderr] 31 | #![feature(external_doc)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `restruct`.
[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 `"docker" "inspect" "a9ed40510443208ef462acf7c19a6ebc56e36221485a3b68e1ac346e697e3da8"`
[INFO] running `"docker" "rm" "-f" "a9ed40510443208ef462acf7c19a6ebc56e36221485a3b68e1ac346e697e3da8"`
[INFO] [stdout] a9ed40510443208ef462acf7c19a6ebc56e36221485a3b68e1ac346e697e3da8