[INFO] fetching crate ent 0.0.4...
[INFO] testing ent-0.0.4 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate ent 0.0.4 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate ent 0.0.4 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ent 0.0.4
[INFO] finished tweaking crates.io crate ent 0.0.4
[INFO] tweaked toml for crates.io crate ent 0.0.4 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bf00148e7b3dee5f500b469a3f56060d18aa60337a7c7c35c384c892b21f9632
[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" "bf00148e7b3dee5f500b469a3f56060d18aa60337a7c7c35c384c892b21f9632", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bf00148e7b3dee5f500b469a3f56060d18aa60337a7c7c35c384c892b21f9632", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bf00148e7b3dee5f500b469a3f56060d18aa60337a7c7c35c384c892b21f9632", kill_on_drop: false }`
[INFO] [stdout] bf00148e7b3dee5f500b469a3f56060d18aa60337a7c7c35c384c892b21f9632
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4d4c1a39a8ca80ec4349e07070444546de7f5ff76158aa5861da31f547481800
[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" "4d4c1a39a8ca80ec4349e07070444546de7f5ff76158aa5861da31f547481800", kill_on_drop: false }`
[INFO] [stderr]    Compiling ent v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `Command { std: "docker" "inspect" "4d4c1a39a8ca80ec4349e07070444546de7f5ff76158aa5861da31f547481800", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d4c1a39a8ca80ec4349e07070444546de7f5ff76158aa5861da31f547481800", kill_on_drop: false }`
[INFO] [stdout] 4d4c1a39a8ca80ec4349e07070444546de7f5ff76158aa5861da31f547481800
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c9e6baa5185ef3eb7a1287e4975f561750d9abf02145868fec3d591f2ed31bc2
[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" "c9e6baa5185ef3eb7a1287e4975f561750d9abf02145868fec3d591f2ed31bc2", kill_on_drop: false }`
[INFO] [stderr]    Compiling ent v0.0.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared crate or module `serde_json`
[INFO] [stdout]   --> tests/basic.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let v: serde_json::Value = serde_json::from_str(r#"{"name":"test"}"#).unwrap();
[INFO] [stdout]    |            ^^^^^^^^^^ use of undeclared crate or module `serde_json`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared crate or module `serde_json`
[INFO] [stdout]   --> tests/basic.rs:10:32
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let v: serde_json::Value = serde_json::from_str(r#"{"name":"test"}"#).unwrap();
[INFO] [stdout]    |                                ^^^^^^^^^^ use of undeclared crate or module `serde_json`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0433`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ent`
[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" "c9e6baa5185ef3eb7a1287e4975f561750d9abf02145868fec3d591f2ed31bc2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9e6baa5185ef3eb7a1287e4975f561750d9abf02145868fec3d591f2ed31bc2", kill_on_drop: false }`
[INFO] [stdout] c9e6baa5185ef3eb7a1287e4975f561750d9abf02145868fec3d591f2ed31bc2