[INFO] fetching crate serde_plugin 0.0.0...
[INFO] testing serde_plugin-0.0.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate serde_plugin 0.0.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate serde_plugin 0.0.0 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serde_plugin 0.0.0
[INFO] finished tweaking crates.io crate serde_plugin 0.0.0
[INFO] tweaked toml for crates.io crate serde_plugin 0.0.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a073b6200750463aa9c79afb6ef245a2ac88dc3bc19ece671b8d4cedbbf3bdb
[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" "1a073b6200750463aa9c79afb6ef245a2ac88dc3bc19ece671b8d4cedbbf3bdb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a073b6200750463aa9c79afb6ef245a2ac88dc3bc19ece671b8d4cedbbf3bdb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a073b6200750463aa9c79afb6ef245a2ac88dc3bc19ece671b8d4cedbbf3bdb", kill_on_drop: false }`
[INFO] [stdout] 1a073b6200750463aa9c79afb6ef245a2ac88dc3bc19ece671b8d4cedbbf3bdb
[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=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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--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] ea77d26fc999a7fa5f5b68a9f142b7b52ff1cd7565a56aa3fbd85cb3960fca4d
[INFO] running `Command { std: "docker" "start" "-a" "ea77d26fc999a7fa5f5b68a9f142b7b52ff1cd7565a56aa3fbd85cb3960fca4d", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_plugin v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: expected item, found `@`
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | @
[INFO] [stdout]   | ^ expected item
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `serde_plugin`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "ea77d26fc999a7fa5f5b68a9f142b7b52ff1cd7565a56aa3fbd85cb3960fca4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea77d26fc999a7fa5f5b68a9f142b7b52ff1cd7565a56aa3fbd85cb3960fca4d", kill_on_drop: false }`
[INFO] [stdout] ea77d26fc999a7fa5f5b68a9f142b7b52ff1cd7565a56aa3fbd85cb3960fca4d