[INFO] cloning repository https://github.com/swuecho/play_json_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/swuecho/play_json_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswuecho%2Fplay_json_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswuecho%2Fplay_json_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1229fa085e3bcdd8c55ddac450be93796268d92e
[INFO] testing swuecho/play_json_rust against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswuecho%2Fplay_json_rust" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/swuecho/play_json_rust on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/swuecho/play_json_rust
[INFO] finished tweaking git repo https://github.com/swuecho/play_json_rust
[INFO] tweaked toml for git repo https://github.com/swuecho/play_json_rust written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/swuecho/play_json_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-1/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "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" "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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "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] fed982e7f0b98790accc08f0dd234fecfcbd1f6fd36b966acd895c9ce3e53329
[INFO] running `Command { std: "docker" "start" "-a" "fed982e7f0b98790accc08f0dd234fecfcbd1f6fd36b966acd895c9ce3e53329", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fed982e7f0b98790accc08f0dd234fecfcbd1f6fd36b966acd895c9ce3e53329", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fed982e7f0b98790accc08f0dd234fecfcbd1f6fd36b966acd895c9ce3e53329", kill_on_drop: false }`
[INFO] [stdout] fed982e7f0b98790accc08f0dd234fecfcbd1f6fd36b966acd895c9ce3e53329
[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" "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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-01-01" "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] 7b8abaeb1d6a4248c902217c0d94ee0d39bf8ab65cbf775c7629b712aaf19d65
[INFO] running `Command { std: "docker" "start" "-a" "7b8abaeb1d6a4248c902217c0d94ee0d39bf8ab65cbf775c7629b712aaf19d65", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling play_json v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved imports `serde::json`, `serde::json`
[INFO] [stdout]  --> src/main.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 5 | use serde::json::{self, Value};
[INFO] [stdout]   |            ^^^^   ^^^^ no `json` in the root
[INFO] [stdout]   |            |
[INFO] [stdout]   |            could not find `json` in `serde`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(convert)]  // as str
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `play_json`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "7b8abaeb1d6a4248c902217c0d94ee0d39bf8ab65cbf775c7629b712aaf19d65", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b8abaeb1d6a4248c902217c0d94ee0d39bf8ab65cbf775c7629b712aaf19d65", kill_on_drop: false }`
[INFO] [stdout] 7b8abaeb1d6a4248c902217c0d94ee0d39bf8ab65cbf775c7629b712aaf19d65