[INFO] fetching crate async-log 2.0.0...
[INFO] checking async-log-2.0.0 against master#90442458ac46b1d5eed752c316da25450f67285b for pr-81477
[INFO] extracting crate async-log 2.0.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate async-log 2.0.0 on toolchain 90442458ac46b1d5eed752c316da25450f67285b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate async-log 2.0.0
[INFO] finished tweaking crates.io crate async-log 2.0.0
[INFO] tweaked toml for crates.io crate async-log 2.0.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate async-log 2.0.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "fetch" "--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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] acf7479b05d5bd131d4b71aa8de4ff428fe870501288f1fe26edde1729e44a03
[INFO] running `Command { std: "docker" "start" "-a" "acf7479b05d5bd131d4b71aa8de4ff428fe870501288f1fe26edde1729e44a03", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "acf7479b05d5bd131d4b71aa8de4ff428fe870501288f1fe26edde1729e44a03", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acf7479b05d5bd131d4b71aa8de4ff428fe870501288f1fe26edde1729e44a03", kill_on_drop: false }`
[INFO] [stdout] acf7479b05d5bd131d4b71aa8de4ff428fe870501288f1fe26edde1729e44a03
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "RUSTFLAGS=--cap-lints=forbid" "-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:ea7d7bff36b2ba8ce4de8bba1d2dea90376bc481f1a945a913994a8c492e40c1" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3a587519be3b6784019afa49ae0e7e4f1e2030faf1b1f7c7d7dfb594d4f8caff
[INFO] running `Command { std: "docker" "start" "-a" "3a587519be3b6784019afa49ae0e7e4f1e2030faf1b1f7c7d7dfb594d4f8caff", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling serde v1.0.98
[INFO] [stderr]     Checking rustc-demangle v0.1.15
[INFO] [stderr]    Compiling backtrace-sys v0.1.29
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]     Checking backtrace v0.3.34
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking serde_json v1.0.40
[INFO] [stderr]    Compiling async-log-attributes v1.0.1
[INFO] [stderr]    Compiling serde_derive v1.0.98
[INFO] [stderr]     Checking async-log v1.1.0
[INFO] [stderr]     Checking async-log v2.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: declaration of a `no_mangle` function
[INFO] [stdout]    --> src/backtrace.rs:14:1
[INFO] [stdout]     |
[INFO] [stdout] 14  | #[no_mangle]
[INFO] [stdout]     | ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:106:11
[INFO] [stdout]     |
[INFO] [stdout] 106 | #![forbid(unsafe_code, future_incompatible, rust_2018_idioms)]
[INFO] [stdout]     |           ^^^^^^^^^^^
[INFO] [stdout]     = note: the linker's behavior with multiple libraries exporting duplicate symbol names is undefined and Rust cannot provide guarantees when you manually override them
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `async-log`
[INFO] [stderr] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[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" "3a587519be3b6784019afa49ae0e7e4f1e2030faf1b1f7c7d7dfb594d4f8caff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a587519be3b6784019afa49ae0e7e4f1e2030faf1b1f7c7d7dfb594d4f8caff", kill_on_drop: false }`
[INFO] [stdout] 3a587519be3b6784019afa49ae0e7e4f1e2030faf1b1f7c7d7dfb594d4f8caff