[INFO] fetching crate fake_serialize 0.1.1...
[INFO] testing fake_serialize-0.1.1 against 1.75.0 for beta-1.76-1
[INFO] extracting crate fake_serialize 0.1.1 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate fake_serialize 0.1.1 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate fake_serialize 0.1.1
[INFO] finished tweaking crates.io crate fake_serialize 0.1.1
[INFO] tweaked toml for crates.io crate fake_serialize 0.1.1 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate crates.io crate fake_serialize 0.1.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] aeec743549b3cfbc0bd9fe0397f231feb006ba652b202359786e012e68caa2cd
[INFO] running `Command { std: "docker" "start" "-a" "aeec743549b3cfbc0bd9fe0397f231feb006ba652b202359786e012e68caa2cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "aeec743549b3cfbc0bd9fe0397f231feb006ba652b202359786e012e68caa2cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aeec743549b3cfbc0bd9fe0397f231feb006ba652b202359786e012e68caa2cd", kill_on_drop: false }`
[INFO] [stdout] aeec743549b3cfbc0bd9fe0397f231feb006ba652b202359786e012e68caa2cd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a975e4a0564bdfe7657055846cbbe0c68745e6f590cc6d4d3f2f94bf6d837c16
[INFO] running `Command { std: "docker" "start" "-a" "a975e4a0564bdfe7657055846cbbe0c68745e6f590cc6d4d3f2f94bf6d837c16", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]    Compiling fake_serialize v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 7.95s
[INFO] running `Command { std: "docker" "inspect" "a975e4a0564bdfe7657055846cbbe0c68745e6f590cc6d4d3f2f94bf6d837c16", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a975e4a0564bdfe7657055846cbbe0c68745e6f590cc6d4d3f2f94bf6d837c16", kill_on_drop: false }`
[INFO] [stdout] a975e4a0564bdfe7657055846cbbe0c68745e6f590cc6d4d3f2f94bf6d837c16
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6256214dd66b3195b489d6190e21156e92a5300fd9f8a2fad0c1480be5f699ee
[INFO] running `Command { std: "docker" "start" "-a" "6256214dd66b3195b489d6190e21156e92a5300fd9f8a2fad0c1480be5f699ee", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]    Compiling fake_serialize v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared crate or module `serde_json`
[INFO] [stdout]   --> examples/constraint.rs:21:20
[INFO] [stdout]    |
[INFO] [stdout] 21 |         let json = serde_json::to_string(t).unwrap();
[INFO] [stdout]    |                    ^^^^^^^^^^ use of undeclared crate or module `serde_json`
[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 E0433`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `fake_serialize` (example "constraint") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: field `i` is never read
[INFO] [stdout]   --> examples/simple.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 23 | struct NotSerializable {
[INFO] [stdout]    |        --------------- field in this struct
[INFO] [stdout] 24 |     i: i16,
[INFO] [stdout]    |     ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `NotSerializable` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "6256214dd66b3195b489d6190e21156e92a5300fd9f8a2fad0c1480be5f699ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6256214dd66b3195b489d6190e21156e92a5300fd9f8a2fad0c1480be5f699ee", kill_on_drop: false }`
[INFO] [stdout] 6256214dd66b3195b489d6190e21156e92a5300fd9f8a2fad0c1480be5f699ee
