[INFO] fetching crate compiler_builtins 0.1.39...
[INFO] checking compiler_builtins-0.1.39 against master#6526e5c772f2da07db745c94ca6bb0a591a39ba4 for pr-80920
[INFO] extracting crate compiler_builtins 0.1.39 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate compiler_builtins 0.1.39 on toolchain 6526e5c772f2da07db745c94ca6bb0a591a39ba4
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6526e5c772f2da07db745c94ca6bb0a591a39ba4" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate compiler_builtins 0.1.39
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate compiler_builtins 0.1.39
[INFO] tweaked toml for crates.io crate compiler_builtins 0.1.39 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate compiler_builtins 0.1.39 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6526e5c772f2da07db745c94ca6bb0a591a39ba4" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+6526e5c772f2da07db745c94ca6bb0a591a39ba4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9db6bd06721bee4afcbcfcbe0f9ce529b335c49cf21302695a9dc0de92c8e5be
[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" "9db6bd06721bee4afcbcfcbe0f9ce529b335c49cf21302695a9dc0de92c8e5be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9db6bd06721bee4afcbcfcbe0f9ce529b335c49cf21302695a9dc0de92c8e5be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9db6bd06721bee4afcbcfcbe0f9ce529b335c49cf21302695a9dc0de92c8e5be", kill_on_drop: false }`
[INFO] [stdout] 9db6bd06721bee4afcbcfcbe0f9ce529b335c49cf21302695a9dc0de92c8e5be
[INFO] running `Command { std: "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" "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" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+6526e5c772f2da07db745c94ca6bb0a591a39ba4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] ba9b8be4f1c964007ca3c5d8d7d0431defaa1314899bfd62c971de92c37d3c4b
[INFO] running `Command { std: "docker" "start" "-a" "ba9b8be4f1c964007ca3c5d8d7d0431defaa1314899bfd62c971de92c37d3c4b", kill_on_drop: false }`
[INFO] [stderr]    Compiling compiler_builtins v0.1.39 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0259]: the name `core` is defined multiple times
[INFO] [stdout]   --> src/lib.rs:32:1
[INFO] [stdout]    |
[INFO] [stdout] 32 | extern crate core;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^ `core` reimported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `core` must be defined only once in the type namespace of this module
[INFO] [stdout] help: you can use `as` to change the binding name of the import
[INFO] [stdout]    |
[INFO] [stdout] 32 | extern crate core as other_core;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0259`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `compiler_builtins`
[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" "ba9b8be4f1c964007ca3c5d8d7d0431defaa1314899bfd62c971de92c37d3c4b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba9b8be4f1c964007ca3c5d8d7d0431defaa1314899bfd62c971de92c37d3c4b", kill_on_drop: false }`
[INFO] [stdout] ba9b8be4f1c964007ca3c5d8d7d0431defaa1314899bfd62c971de92c37d3c4b