[INFO] cloning repository https://github.com/njsfield/rust-json-parse-exercise
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/njsfield/rust-json-parse-exercise" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnjsfield%2Frust-json-parse-exercise", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnjsfield%2Frust-json-parse-exercise'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a9807567f8cd85ba49d1319597a5c79157d73d92
[INFO] checking njsfield/rust-json-parse-exercise against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnjsfield%2Frust-json-parse-exercise" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/njsfield/rust-json-parse-exercise on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/njsfield/rust-json-parse-exercise
[INFO] finished tweaking git repo https://github.com/njsfield/rust-json-parse-exercise
[INFO] tweaked toml for git repo https://github.com/njsfield/rust-json-parse-exercise written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/njsfield/rust-json-parse-exercise 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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded regex v1.7.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f035262c5a60abddf81160dd0b442fbb22017b3ba665e11f725a5a4f03d962ba
[INFO] running `Command { std: "docker" "start" "-a" "f035262c5a60abddf81160dd0b442fbb22017b3ba665e11f725a5a4f03d962ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f035262c5a60abddf81160dd0b442fbb22017b3ba665e11f725a5a4f03d962ba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f035262c5a60abddf81160dd0b442fbb22017b3ba665e11f725a5a4f03d962ba", kill_on_drop: false }`
[INFO] [stdout] f035262c5a60abddf81160dd0b442fbb22017b3ba665e11f725a5a4f03d962ba
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b112873778f5701cc4a6f121f3fe7ad77da74d5839db5c198c9072b201e0a92a
[INFO] running `Command { std: "docker" "start" "-a" "b112873778f5701cc4a6f121f3fe7ad77da74d5839db5c198c9072b201e0a92a", kill_on_drop: false }`
[INFO] [stderr]     Checking regex-syntax v0.6.29
[INFO] [stderr]     Checking regex v1.7.3
[INFO] [stderr]     Checking rust-json-parse-exercise v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.64s
[INFO] running `Command { std: "docker" "inspect" "b112873778f5701cc4a6f121f3fe7ad77da74d5839db5c198c9072b201e0a92a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b112873778f5701cc4a6f121f3fe7ad77da74d5839db5c198c9072b201e0a92a", kill_on_drop: false }`
[INFO] [stdout] b112873778f5701cc4a6f121f3fe7ad77da74d5839db5c198c9072b201e0a92a
[INFO] checking njsfield/rust-json-parse-exercise against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnjsfield%2Frust-json-parse-exercise" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/njsfield/rust-json-parse-exercise on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/njsfield/rust-json-parse-exercise
[INFO] finished tweaking git repo https://github.com/njsfield/rust-json-parse-exercise
[INFO] tweaked toml for git repo https://github.com/njsfield/rust-json-parse-exercise written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/njsfield/rust-json-parse-exercise 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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 892b5cc56d8709d77e7925ce1de04f1aa67a0e90f07d7800d4d0b079360e5065
[INFO] running `Command { std: "docker" "start" "-a" "892b5cc56d8709d77e7925ce1de04f1aa67a0e90f07d7800d4d0b079360e5065", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "892b5cc56d8709d77e7925ce1de04f1aa67a0e90f07d7800d4d0b079360e5065", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "892b5cc56d8709d77e7925ce1de04f1aa67a0e90f07d7800d4d0b079360e5065", kill_on_drop: false }`
[INFO] [stdout] 892b5cc56d8709d77e7925ce1de04f1aa67a0e90f07d7800d4d0b079360e5065
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5da9bc7dfedb6e69de06d4567882d74607f2928ec1a76a792b5b8dc98e07e384
[INFO] running `Command { std: "docker" "start" "-a" "5da9bc7dfedb6e69de06d4567882d74607f2928ec1a76a792b5b8dc98e07e384", kill_on_drop: false }`
[INFO] [stderr]     Checking regex-syntax v0.6.29
[INFO] [stderr]     Checking regex v1.7.3
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/regex-1.7.3/src/exec.rs:848:13
[INFO] [stdout]     |
[INFO] [stdout] 848 | /             match dfa::Fsm::reverse(
[INFO] [stdout] 849 | |                 &self.ro.dfa_reverse,
[INFO] [stdout] 850 | |                 self.cache.value(),
[INFO] [stdout] 851 | |                 false,
[INFO] [stdout] ...   |
[INFO] [stdout] 862 | |                 Quit => return Some(Quit),
[INFO] [stdout] 863 | |             };
[INFO] [stdout]     | |_____________^ cannot infer type
[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 E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `regex` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "5da9bc7dfedb6e69de06d4567882d74607f2928ec1a76a792b5b8dc98e07e384", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5da9bc7dfedb6e69de06d4567882d74607f2928ec1a76a792b5b8dc98e07e384", kill_on_drop: false }`
[INFO] [stdout] 5da9bc7dfedb6e69de06d4567882d74607f2928ec1a76a792b5b8dc98e07e384