[INFO] fetching crate fake_serialize 0.1.1...
[INFO] checking fake_serialize-0.1.1 against master#af4a5a13a15fa0c60e06321077ef452f769b42fd for pr-122960-3
[INFO] extracting crate fake_serialize 0.1.1 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate fake_serialize 0.1.1 on toolchain af4a5a13a15fa0c60e06321077ef452f769b42fd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "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-7-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" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded proc-macro2 v1.0.7
[INFO] [stderr]   Downloaded syn v1.0.13
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c1ce5ce0d2f598acf4de1e22f309dbf5e050e1932b4fc8fa4ae04fb4d9f8e7e0
[INFO] running `Command { std: "docker" "start" "-a" "c1ce5ce0d2f598acf4de1e22f309dbf5e050e1932b4fc8fa4ae04fb4d9f8e7e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c1ce5ce0d2f598acf4de1e22f309dbf5e050e1932b4fc8fa4ae04fb4d9f8e7e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c1ce5ce0d2f598acf4de1e22f309dbf5e050e1932b4fc8fa4ae04fb4d9f8e7e0", kill_on_drop: false }`
[INFO] [stdout] c1ce5ce0d2f598acf4de1e22f309dbf5e050e1932b4fc8fa4ae04fb4d9f8e7e0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a7704ab21b7a98097114a00a11326a318f9e2750cd42b3f5db70ead41aad4e0e
[INFO] running `Command { std: "docker" "start" "-a" "a7704ab21b7a98097114a00a11326a318f9e2750cd42b3f5db70ead41aad4e0e", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]     Checking quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]     Checking 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 1 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" "a7704ab21b7a98097114a00a11326a318f9e2750cd42b3f5db70ead41aad4e0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7704ab21b7a98097114a00a11326a318f9e2750cd42b3f5db70ead41aad4e0e", kill_on_drop: false }`
[INFO] [stdout] a7704ab21b7a98097114a00a11326a318f9e2750cd42b3f5db70ead41aad4e0e