[INFO] crate context-attribute 1.0.0 is already in cache
[INFO] checking context-attribute-1.0.0 against try#d27c6c6a469a28343396a8f3ac1c9d403aabda69 for pr-66037
[INFO] extracting crate context-attribute 1.0.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate context-attribute 1.0.0 on toolchain d27c6c6a469a28343396a8f3ac1c9d403aabda69
[INFO] running `"/workspace/cargo-home/bin/cargo" "+d27c6c6a469a28343396a8f3ac1c9d403aabda69" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate context-attribute 1.0.0
[INFO] finished tweaking crates.io crate context-attribute 1.0.0
[INFO] tweaked toml for crates.io crate context-attribute 1.0.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+d27c6c6a469a28343396a8f3ac1c9d403aabda69" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+d27c6c6a469a28343396a8f3ac1c9d403aabda69" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=forbid" "-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" "+d27c6c6a469a28343396a8f3ac1c9d403aabda69" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] d419fee681ac35d9080908c3c8737bf6d96318dba22e6bd8ff101ab4d9f185dc
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "d419fee681ac35d9080908c3c8737bf6d96318dba22e6bd8ff101ab4d9f185dc"`
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]     Checking syn v0.15.44
[INFO] [stderr]    Compiling backtrace v0.3.41
[INFO] [stderr]    Compiling failure v0.1.6
[INFO] [stderr]     Checking context-attribute v1.0.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: unused extern crate
[INFO] [stderr]   --> src/lib.rs:45:1
[INFO] [stderr]    |
[INFO] [stderr] 45 | extern crate proc_macro;
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stderr]    |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]   --> src/lib.rs:39:45
[INFO] [stderr]    |
[INFO] [stderr] 39 | #![forbid(unsafe_code, future_incompatible, rust_2018_idioms)]
[INFO] [stderr]    |                                             ^^^^^^^^^^^^^^^^
[INFO] [stderr]    = note: `#[forbid(unused_extern_crates)]` implied by `#[forbid(rust_2018_idioms)]`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `context-attribute`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: unused extern crate
[INFO] [stderr]   --> src/lib.rs:45:1
[INFO] [stderr]    |
[INFO] [stderr] 45 | extern crate proc_macro;
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stderr]    |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]   --> src/lib.rs:39:45
[INFO] [stderr]    |
[INFO] [stderr] 39 | #![forbid(unsafe_code, future_incompatible, rust_2018_idioms)]
[INFO] [stderr]    |                                             ^^^^^^^^^^^^^^^^
[INFO] [stderr]    = note: `#[forbid(unused_extern_crates)]` implied by `#[forbid(rust_2018_idioms)]`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `context-attribute`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "d419fee681ac35d9080908c3c8737bf6d96318dba22e6bd8ff101ab4d9f185dc"`
[INFO] running `"docker" "rm" "-f" "d419fee681ac35d9080908c3c8737bf6d96318dba22e6bd8ff101ab4d9f185dc"`
[INFO] [stdout] d419fee681ac35d9080908c3c8737bf6d96318dba22e6bd8ff101ab4d9f185dc