[INFO] crate sp-rpc 2.0.0-rc4 is already in cache
[INFO] testing sp-rpc-2.0.0-rc4 against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409
[INFO] extracting crate sp-rpc 2.0.0-rc4 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate sp-rpc 2.0.0-rc4 on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate sp-rpc 2.0.0-rc4
[INFO] finished tweaking crates.io crate sp-rpc 2.0.0-rc4
[INFO] tweaked toml for crates.io crate sp-rpc 2.0.0-rc4 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9e5c5a9a62ce81568b0876584b5259911cdcfb8e070cf4c38c0a90b0a53d6927
[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" "9e5c5a9a62ce81568b0876584b5259911cdcfb8e070cf4c38c0a90b0a53d6927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e5c5a9a62ce81568b0876584b5259911cdcfb8e070cf4c38c0a90b0a53d6927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e5c5a9a62ce81568b0876584b5259911cdcfb8e070cf4c38c0a90b0a53d6927", kill_on_drop: false }`
[INFO] [stdout] 9e5c5a9a62ce81568b0876584b5259911cdcfb8e070cf4c38c0a90b0a53d6927
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "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] 41ff38797a2a741a6ad3505e8be8b8e8660f3d632b5e785a1665f9f118809df0
[INFO] running `Command { std: "docker" "start" "-a" "41ff38797a2a741a6ad3505e8be8b8e8660f3d632b5e785a1665f9f118809df0", kill_on_drop: false }`
[INFO] [stderr]    Compiling either v1.5.3
[INFO] [stderr]    Compiling parity-util-mem v0.7.0
[INFO] [stderr]    Compiling hash-db v0.15.2
[INFO] [stderr]    Compiling libsecp256k1 v0.3.5
[INFO] [stderr]    Compiling bitvec v0.17.4
[INFO] [stderr]    Compiling parity-scale-codec v1.3.1
[INFO] [stderr]    Compiling impl-codec v0.4.2
[INFO] [stderr]    Compiling sp-wasm-interface v2.0.0-rc5
[INFO] [stderr]    Compiling sp-externalities v0.8.0-rc5
[INFO] [stderr]    Compiling primitive-types v0.7.2
[INFO] [stderr]    Compiling sp-runtime-interface v2.0.0-rc5
[INFO] [stderr]    Compiling sp-core v2.0.0-rc5
[INFO] [stderr]    Compiling sp-rpc v2.0.0-rc4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 27.91s
[INFO] running `Command { std: "docker" "inspect" "41ff38797a2a741a6ad3505e8be8b8e8660f3d632b5e785a1665f9f118809df0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "41ff38797a2a741a6ad3505e8be8b8e8660f3d632b5e785a1665f9f118809df0", kill_on_drop: false }`
[INFO] [stdout] 41ff38797a2a741a6ad3505e8be8b8e8660f3d632b5e785a1665f9f118809df0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "test" "--frozen" "--no-run" "--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] 399b9420cdd9191adcf10c8f9894fcfee41a32f12317b1a98564429e5a54f756
[INFO] running `Command { std: "docker" "start" "-a" "399b9420cdd9191adcf10c8f9894fcfee41a32f12317b1a98564429e5a54f756", kill_on_drop: false }`
[INFO] [stderr]    Compiling sp-rpc v2.0.0-rc4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `serde_json`
[INFO] [stdout]   --> src/lib.rs:31:3
[INFO] [stdout]    |
[INFO] [stdout] 31 |         serde_json::from_str::<T>(s).unwrap(),
[INFO] [stdout]    |         ^^^^^^^^^^ use of undeclared type or module `serde_json`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared type or module `serde_json`
[INFO] [stdout]   --> src/lib.rs:35:3
[INFO] [stdout]    |
[INFO] [stdout] 35 |         serde_json::to_string(&expected).unwrap(),
[INFO] [stdout]    |         ^^^^^^^^^^ use of undeclared type 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 `sp-rpc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "399b9420cdd9191adcf10c8f9894fcfee41a32f12317b1a98564429e5a54f756", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "399b9420cdd9191adcf10c8f9894fcfee41a32f12317b1a98564429e5a54f756", kill_on_drop: false }`
[INFO] [stdout] 399b9420cdd9191adcf10c8f9894fcfee41a32f12317b1a98564429e5a54f756