[INFO] fetching crate async-log 2.0.0...
[INFO] testing async-log-2.0.0 against master#cdb45c87e2cd43495379f7e867e3cc15dcee9f93 for pr-145838-1
[INFO] extracting crate async-log 2.0.0 into /workspace/builds/worker-4-tc1/source
[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-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate async-log 2.0.0 on toolchain cdb45c87e2cd43495379f7e867e3cc15dcee9f93
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate async-log 2.0.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 867560c05a3447e7fe692fa8fc35bac46a2ba47f3e793a07ac908030bc1badfb
[INFO] running `Command { std: "docker" "start" "-a" "867560c05a3447e7fe692fa8fc35bac46a2ba47f3e793a07ac908030bc1badfb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "867560c05a3447e7fe692fa8fc35bac46a2ba47f3e793a07ac908030bc1badfb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "867560c05a3447e7fe692fa8fc35bac46a2ba47f3e793a07ac908030bc1badfb", kill_on_drop: false }`
[INFO] [stdout] 867560c05a3447e7fe692fa8fc35bac46a2ba47f3e793a07ac908030bc1badfb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+cdb45c87e2cd43495379f7e867e3cc15dcee9f93" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 961b2c96bf458f850120e5eaf0714be674f7d00d84cb4f2b7cbce855f7fad907
[INFO] running `Command { std: "docker" "start" "-a" "961b2c96bf458f850120e5eaf0714be674f7d00d84cb4f2b7cbce855f7fad907", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling rustc-demangle v0.1.15
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling backtrace-sys v0.1.29
[INFO] [stderr]    Compiling backtrace v0.3.34
[INFO] [stderr]    Compiling async-log-attributes v1.0.1
[INFO] [stderr]    Compiling 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 linker's behavior with multiple libraries exporting duplicate symbol names is undefined and Rust cannot provide guarantees when you manually override them
[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] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `async-log` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "961b2c96bf458f850120e5eaf0714be674f7d00d84cb4f2b7cbce855f7fad907", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "961b2c96bf458f850120e5eaf0714be674f7d00d84cb4f2b7cbce855f7fad907", kill_on_drop: false }`
[INFO] [stdout] 961b2c96bf458f850120e5eaf0714be674f7d00d84cb4f2b7cbce855f7fad907