[INFO] fetching crate ent 0.0.4...
[INFO] testing ent-0.0.4 against 1.54.0 for beta-1.55-1
[INFO] extracting crate ent 0.0.4 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate ent 0.0.4 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", 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] 8ddaaae614062cbbd820db81ad25c3c84a91117d43ccf79db16acc77fe94e933
[INFO] running `Command { std: "docker" "start" "-a" "8ddaaae614062cbbd820db81ad25c3c84a91117d43ccf79db16acc77fe94e933", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8ddaaae614062cbbd820db81ad25c3c84a91117d43ccf79db16acc77fe94e933", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ddaaae614062cbbd820db81ad25c3c84a91117d43ccf79db16acc77fe94e933", kill_on_drop: false }`
[INFO] [stdout] 8ddaaae614062cbbd820db81ad25c3c84a91117d43ccf79db16acc77fe94e933
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "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] cdad775dfb40e92450535d48dbe10a3515ce5e05715383e9948e1e5c9c515723
[INFO] running `Command { std: "docker" "start" "-a" "cdad775dfb40e92450535d48dbe10a3515ce5e05715383e9948e1e5c9c515723", kill_on_drop: false }`
[INFO] [stderr]    Compiling ent v0.0.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.37s
[INFO] running `Command { std: "docker" "inspect" "cdad775dfb40e92450535d48dbe10a3515ce5e05715383e9948e1e5c9c515723", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cdad775dfb40e92450535d48dbe10a3515ce5e05715383e9948e1e5c9c515723", kill_on_drop: false }`
[INFO] [stdout] cdad775dfb40e92450535d48dbe10a3515ce5e05715383e9948e1e5c9c515723
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0cddfee2c311c750af0efd6cd6c687564f5ed79adbb44e920d041267a529a3cc
[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" "0cddfee2c311c750af0efd6cd6c687564f5ed79adbb44e920d041267a529a3cc", 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" "0cddfee2c311c750af0efd6cd6c687564f5ed79adbb44e920d041267a529a3cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0cddfee2c311c750af0efd6cd6c687564f5ed79adbb44e920d041267a529a3cc", kill_on_drop: false }`
[INFO] [stdout] 0cddfee2c311c750af0efd6cd6c687564f5ed79adbb44e920d041267a529a3cc
