[INFO] fetching crate fake_serialize 0.1.1...
[INFO] testing fake_serialize-0.1.1 against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] extracting crate fake_serialize 0.1.1 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate fake_serialize 0.1.1 on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "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-13/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: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "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] 547dcb21b71f4e0088783cca9e6ddecb8c53f731dac6f0b213ba276aca4b9927
[INFO] running `Command { std: "docker" "start" "-a" "547dcb21b71f4e0088783cca9e6ddecb8c53f731dac6f0b213ba276aca4b9927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "547dcb21b71f4e0088783cca9e6ddecb8c53f731dac6f0b213ba276aca4b9927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "547dcb21b71f4e0088783cca9e6ddecb8c53f731dac6f0b213ba276aca4b9927", kill_on_drop: false }`
[INFO] [stdout] 547dcb21b71f4e0088783cca9e6ddecb8c53f731dac6f0b213ba276aca4b9927
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8b27b55260046b8c74fa81a52c29be71fb9bf91d731e81d9379c0538369b351a
[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" "8b27b55260046b8c74fa81a52c29be71fb9bf91d731e81d9379c0538369b351a", 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 quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.104
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling fake_serialize v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 24.87s
[INFO] running `Command { std: "docker" "inspect" "8b27b55260046b8c74fa81a52c29be71fb9bf91d731e81d9379c0538369b351a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b27b55260046b8c74fa81a52c29be71fb9bf91d731e81d9379c0538369b351a", kill_on_drop: false }`
[INFO] [stdout] 8b27b55260046b8c74fa81a52c29be71fb9bf91d731e81d9379c0538369b351a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 07278428229e182213ff21eec83985b0dd11e90158aec87b167ef2f55d59039e
[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" "07278428229e182213ff21eec83985b0dd11e90158aec87b167ef2f55d59039e", kill_on_drop: false }`
[INFO] [stderr]    Compiling fake_serialize v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `i`
[INFO] [stdout]   --> examples/simple.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 |     i: i16,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[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` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "07278428229e182213ff21eec83985b0dd11e90158aec87b167ef2f55d59039e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "07278428229e182213ff21eec83985b0dd11e90158aec87b167ef2f55d59039e", kill_on_drop: false }`
[INFO] [stdout] 07278428229e182213ff21eec83985b0dd11e90158aec87b167ef2f55d59039e