[INFO] fetching crate libgrep-rs 0.1.4...
[INFO] checking libgrep-rs-0.1.4 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate libgrep-rs 0.1.4 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate libgrep-rs 0.1.4 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 crates.io crate libgrep-rs 0.1.4
[INFO] finished tweaking crates.io crate libgrep-rs 0.1.4
[INFO] tweaked toml for crates.io crate libgrep-rs 0.1.4 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate crates.io crate libgrep-rs 0.1.4 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] 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] a6121c751c45ca562f4c6d3737934f3e3523f5ca70039a288cbc5e4eca3d7caf
[INFO] running `Command { std: "docker" "start" "-a" "a6121c751c45ca562f4c6d3737934f3e3523f5ca70039a288cbc5e4eca3d7caf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a6121c751c45ca562f4c6d3737934f3e3523f5ca70039a288cbc5e4eca3d7caf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6121c751c45ca562f4c6d3737934f3e3523f5ca70039a288cbc5e4eca3d7caf", kill_on_drop: false }`
[INFO] [stdout] a6121c751c45ca562f4c6d3737934f3e3523f5ca70039a288cbc5e4eca3d7caf
[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] def4d4f0b49f72be60bfe50d6fbf59a986f51654e0dfd71fe3a4819cf332f0f8
[INFO] running `Command { std: "docker" "start" "-a" "def4d4f0b49f72be60bfe50d6fbf59a986f51654e0dfd71fe3a4819cf332f0f8", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.10
[INFO] [stderr]     Checking regex v1.3.7
[INFO] [stderr]     Checking libgrep-rs v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:179:13
[INFO] [stdout]     |
[INFO] [stdout] 179 |         let mut return_text: String = searcher.search();
[INFO] [stdout]     |             ----^^^^^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.37s
[INFO] running `Command { std: "docker" "inspect" "def4d4f0b49f72be60bfe50d6fbf59a986f51654e0dfd71fe3a4819cf332f0f8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "def4d4f0b49f72be60bfe50d6fbf59a986f51654e0dfd71fe3a4819cf332f0f8", kill_on_drop: false }`
[INFO] [stdout] def4d4f0b49f72be60bfe50d6fbf59a986f51654e0dfd71fe3a4819cf332f0f8
[INFO] checking libgrep-rs-0.1.4 against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] extracting crate libgrep-rs 0.1.4 into /workspace/builds/worker-6-tc2/source
[INFO] validating manifest of crates.io crate libgrep-rs 0.1.4 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 crates.io crate libgrep-rs 0.1.4
[INFO] finished tweaking crates.io crate libgrep-rs 0.1.4
[INFO] tweaked toml for crates.io crate libgrep-rs 0.1.4 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate crates.io crate libgrep-rs 0.1.4 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] 3f85f0248b892b026659c96f3029c3830443797f2a91c86572295e0a45853653
[INFO] running `Command { std: "docker" "start" "-a" "3f85f0248b892b026659c96f3029c3830443797f2a91c86572295e0a45853653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3f85f0248b892b026659c96f3029c3830443797f2a91c86572295e0a45853653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f85f0248b892b026659c96f3029c3830443797f2a91c86572295e0a45853653", kill_on_drop: false }`
[INFO] [stdout] 3f85f0248b892b026659c96f3029c3830443797f2a91c86572295e0a45853653
[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] 4e5daaceff247200d0a0b19ed963844a95ee4eab05911e8cb7fe3f33e397d638
[INFO] running `Command { std: "docker" "start" "-a" "4e5daaceff247200d0a0b19ed963844a95ee4eab05911e8cb7fe3f33e397d638", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.10
[INFO] [stderr]     Checking regex v1.3.7
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/regex-1.3.7/src/exec.rs:836:13
[INFO] [stdout]     |
[INFO] [stdout] 836 | /             match dfa::Fsm::reverse(
[INFO] [stdout] 837 | |                 &self.ro.dfa_reverse,
[INFO] [stdout] 838 | |                 self.cache.value(),
[INFO] [stdout] 839 | |                 false,
[INFO] [stdout] ...   |
[INFO] [stdout] 850 | |                 Quit => return Some(Quit),
[INFO] [stdout] 851 | |             };
[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" "4e5daaceff247200d0a0b19ed963844a95ee4eab05911e8cb7fe3f33e397d638", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e5daaceff247200d0a0b19ed963844a95ee4eab05911e8cb7fe3f33e397d638", kill_on_drop: false }`
[INFO] [stdout] 4e5daaceff247200d0a0b19ed963844a95ee4eab05911e8cb7fe3f33e397d638