[INFO] fetching crate async-log 2.0.0...
[INFO] checking async-log-2.0.0 against master#836c31742687ba4e2f857b5b698e1e9e6b67619c for pr-81789
[INFO] extracting crate async-log 2.0.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate async-log 2.0.0 on toolchain 836c31742687ba4e2f857b5b698e1e9e6b67619c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "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-1/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" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 065bd1c2a6b49df83cca8cb9f345db805d72efe6da38ce21cd1479ca5580ba63
[INFO] running `Command { std: "docker" "start" "-a" "065bd1c2a6b49df83cca8cb9f345db805d72efe6da38ce21cd1479ca5580ba63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "065bd1c2a6b49df83cca8cb9f345db805d72efe6da38ce21cd1479ca5580ba63", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "065bd1c2a6b49df83cca8cb9f345db805d72efe6da38ce21cd1479ca5580ba63", kill_on_drop: false }`
[INFO] [stdout] 065bd1c2a6b49df83cca8cb9f345db805d72efe6da38ce21cd1479ca5580ba63
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+836c31742687ba4e2f857b5b698e1e9e6b67619c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 61ea1e3ea5c9f4aa823c31adf35caeec6beb7ae2f76a1b35646e1c2dde9be256
[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" "61ea1e3ea5c9f4aa823c31adf35caeec6beb7ae2f76a1b35646e1c2dde9be256", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]     Checking lazy_static v1.3.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]    Compiling serde v1.0.98
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]     Checking scopeguard v1.0.0
[INFO] [stderr]     Checking rustc-demangle v0.1.15
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking regex-syntax v0.6.7
[INFO] [stderr]     Checking lock_api v0.3.1
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling backtrace-sys v0.1.29
[INFO] [stderr]     Checking aho-corasick v0.7.3
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]     Checking parking_lot v0.9.0
[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] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `async-log`
[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 `Command { std: "docker" "inspect" "61ea1e3ea5c9f4aa823c31adf35caeec6beb7ae2f76a1b35646e1c2dde9be256", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61ea1e3ea5c9f4aa823c31adf35caeec6beb7ae2f76a1b35646e1c2dde9be256", kill_on_drop: false }`
[INFO] [stdout] 61ea1e3ea5c9f4aa823c31adf35caeec6beb7ae2f76a1b35646e1c2dde9be256