[INFO] fetching crate varcon 0.5.1...
[INFO] testing varcon-0.5.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate varcon 0.5.1 into /workspace/builds/worker-91/source
[INFO] validating manifest of crates.io crate varcon 0.5.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate varcon 0.5.1
[INFO] finished tweaking crates.io crate varcon 0.5.1
[INFO] tweaked toml for crates.io crate varcon 0.5.1 written to /workspace/builds/worker-91/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-91/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-91/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f91fa5c41550b55cbdc9aa08bf5d5afdff089c95c7014c61bac81cc6bea5988a
[INFO] running `Command { std: "docker" "start" "-a" "f91fa5c41550b55cbdc9aa08bf5d5afdff089c95c7014c61bac81cc6bea5988a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f91fa5c41550b55cbdc9aa08bf5d5afdff089c95c7014c61bac81cc6bea5988a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f91fa5c41550b55cbdc9aa08bf5d5afdff089c95c7014c61bac81cc6bea5988a", kill_on_drop: false }`
[INFO] [stdout] f91fa5c41550b55cbdc9aa08bf5d5afdff089c95c7014c61bac81cc6bea5988a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-91/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-91/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f6c4418d11b18382f9f7c6b8c2a62b30ce517ba8100036b5c9380f1d81b5289f
[INFO] running `Command { std: "docker" "start" "-a" "f6c4418d11b18382f9f7c6b8c2a62b30ce517ba8100036b5c9380f1d81b5289f", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling enumflags2_derive v0.7.0
[INFO] [stderr]    Compiling enumflags2 v0.7.1
[INFO] [stderr]    Compiling varcon-core v2.1.1
[INFO] [stderr]    Compiling varcon v0.5.1 (/opt/rustwide/workdir)
[INFO] [stderr] error: could not compile `varcon`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name varcon --edition=2018 src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="all"' --cfg 'feature="default"' --cfg 'feature="flags"' -C metadata=122079616914d04a -C extra-filename=-122079616914d04a --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern varcon_core=/opt/rustwide/target/debug/deps/libvarcon_core-655199c27aa4dae0.rmeta --cap-lints=warn` (signal: 9, SIGKILL: kill)
[INFO] running `Command { std: "docker" "inspect" "f6c4418d11b18382f9f7c6b8c2a62b30ce517ba8100036b5c9380f1d81b5289f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f6c4418d11b18382f9f7c6b8c2a62b30ce517ba8100036b5c9380f1d81b5289f", kill_on_drop: false }`
[INFO] [stdout] f6c4418d11b18382f9f7c6b8c2a62b30ce517ba8100036b5c9380f1d81b5289f