[INFO] cloning repository https://github.com/howlowck/learn-ml-in-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/howlowck/learn-ml-in-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhowlowck%2Flearn-ml-in-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhowlowck%2Flearn-ml-in-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0f1a5e20c5e3eb14c70a4fb2fee0b3962d99da12
[INFO] checking howlowck/learn-ml-in-rust against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhowlowck%2Flearn-ml-in-rust" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/howlowck/learn-ml-in-rust 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/howlowck/learn-ml-in-rust
[INFO] finished tweaking git repo https://github.com/howlowck/learn-ml-in-rust
[INFO] tweaked toml for git repo https://github.com/howlowck/learn-ml-in-rust written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/howlowck/learn-ml-in-rust 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 console v0.7.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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 }`
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[INFO] running `Command { std: "docker" "start" "-a" "f138eae94afe4e981b284ca93903cd28986df1bb2e0fcb2dbc7ca1490f6046ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f138eae94afe4e981b284ca93903cd28986df1bb2e0fcb2dbc7ca1490f6046ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f138eae94afe4e981b284ca93903cd28986df1bb2e0fcb2dbc7ca1490f6046ed", kill_on_drop: false }`
[INFO] [stdout] f138eae94afe4e981b284ca93903cd28986df1bb2e0fcb2dbc7ca1490f6046ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] b49c82b67eb1de89a24bd9667fc7062240f24ef89892428c8e830f504200f7f0
[INFO] running `Command { std: "docker" "start" "-a" "b49c82b67eb1de89a24bd9667fc7062240f24ef89892428c8e830f504200f7f0", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.46
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling autocfg v0.1.1
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking stable_deref_trait v1.1.1
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]     Checking unreachable v1.0.0
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[INFO] [stderr]     Checking smallvec v0.6.7
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]     Checking rand_hc v0.1.0
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[INFO] [stderr]     Checking rand_xorshift v0.1.1
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[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling regex v1.1.0
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[INFO] [stderr]    Compiling rand_pcg v0.1.1
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[INFO] [stderr]     Checking learn-ml-in-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.02s
[INFO] running `Command { std: "docker" "inspect" "b49c82b67eb1de89a24bd9667fc7062240f24ef89892428c8e830f504200f7f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b49c82b67eb1de89a24bd9667fc7062240f24ef89892428c8e830f504200f7f0", kill_on_drop: false }`
[INFO] [stdout] b49c82b67eb1de89a24bd9667fc7062240f24ef89892428c8e830f504200f7f0
[INFO] checking howlowck/learn-ml-in-rust against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhowlowck%2Flearn-ml-in-rust" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/howlowck/learn-ml-in-rust 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/howlowck/learn-ml-in-rust
[INFO] finished tweaking git repo https://github.com/howlowck/learn-ml-in-rust
[INFO] tweaked toml for git repo https://github.com/howlowck/learn-ml-in-rust written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/howlowck/learn-ml-in-rust 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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 8eaabe86720563de8ebd88de62e22623992ecd735e5ff7984ad3ffafc2f878b5
[INFO] running `Command { std: "docker" "start" "-a" "8eaabe86720563de8ebd88de62e22623992ecd735e5ff7984ad3ffafc2f878b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8eaabe86720563de8ebd88de62e22623992ecd735e5ff7984ad3ffafc2f878b5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8eaabe86720563de8ebd88de62e22623992ecd735e5ff7984ad3ffafc2f878b5", kill_on_drop: false }`
[INFO] [stdout] 8eaabe86720563de8ebd88de62e22623992ecd735e5ff7984ad3ffafc2f878b5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] fa9eb98a4342dcdd6970763314cbd66b5132c0e33c67d850a3fb857dd4771266
[INFO] running `Command { std: "docker" "start" "-a" "fa9eb98a4342dcdd6970763314cbd66b5132c0e33c67d850a3fb857dd4771266", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.46
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]    Compiling autocfg v0.1.1
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]     Checking stable_deref_trait v1.1.1
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]     Checking owning_ref v0.4.0
[INFO] [stderr]     Checking smallvec v0.6.7
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]    Compiling memchr v2.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.4
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking lock_api v0.1.5
[INFO] [stderr]     Checking regex-syntax v0.6.4
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking utf8-ranges v1.0.2
[INFO] [stderr]     Checking textwrap v0.10.0
[INFO] [stderr]    Compiling rand_pcg v0.1.1
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking strsim v0.7.0
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking rand_os v0.1.1
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking clap v2.32.0
[INFO] [stderr]     Checking aho-corasick v0.6.9
[INFO] [stderr]     Checking parking_lot v0.7.1
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/regex-1.1.0/src/exec.rs:754:13
[INFO] [stdout]     |
[INFO] [stdout] 754 | /             match dfa::Fsm::reverse(
[INFO] [stdout] 755 | |                 &self.ro.dfa_reverse,
[INFO] [stdout] 756 | |                 self.cache,
[INFO] [stdout] 757 | |                 false,
[INFO] [stdout] ...   |
[INFO] [stdout] 764 | |                 Quit => return Some(Quit),
[INFO] [stdout] 765 | |             };
[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" "fa9eb98a4342dcdd6970763314cbd66b5132c0e33c67d850a3fb857dd4771266", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fa9eb98a4342dcdd6970763314cbd66b5132c0e33c67d850a3fb857dd4771266", kill_on_drop: false }`
[INFO] [stdout] fa9eb98a4342dcdd6970763314cbd66b5132c0e33c67d850a3fb857dd4771266