[INFO] cloning repository https://github.com/modeverv/Rust2020_socket_programing
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/modeverv/Rust2020_socket_programing" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmodeverv%2FRust2020_socket_programing", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmodeverv%2FRust2020_socket_programing'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] becde9cdf219416cce88ff639a40af5c1401bb22
[INFO] checking modeverv/Rust2020_socket_programing against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmodeverv%2FRust2020_socket_programing" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/modeverv/Rust2020_socket_programing 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/modeverv/Rust2020_socket_programing
[INFO] finished tweaking git repo https://github.com/modeverv/Rust2020_socket_programing
[INFO] tweaked toml for git repo https://github.com/modeverv/Rust2020_socket_programing written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/modeverv/Rust2020_socket_programing 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 aho-corasick v0.7.7
[INFO] [stderr]   Downloaded backtrace v0.3.43
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] c34d5e5482a008c9c379b70c308196bb118b8ef7a455670149667772c9255da1
[INFO] running `Command { std: "docker" "start" "-a" "c34d5e5482a008c9c379b70c308196bb118b8ef7a455670149667772c9255da1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c34d5e5482a008c9c379b70c308196bb118b8ef7a455670149667772c9255da1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c34d5e5482a008c9c379b70c308196bb118b8ef7a455670149667772c9255da1", kill_on_drop: false }`
[INFO] [stdout] c34d5e5482a008c9c379b70c308196bb118b8ef7a455670149667772c9255da1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 5dcba900df145db58eaf284b8278b20814b6855417b3c764e7904b3f97f3ec5d
[INFO] running `Command { std: "docker" "start" "-a" "5dcba900df145db58eaf284b8278b20814b6855417b3c764e7904b3f97f3ec5d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling cc v1.0.50
[INFO] [stderr]    Compiling memchr v2.3.0
[INFO] [stderr]    Compiling failure_derive v0.1.6
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking regex-syntax v0.6.14
[INFO] [stderr]     Checking quick-error v1.2.3
[INFO] [stderr]     Checking rustc-demangle v0.1.16
[INFO] [stderr]     Checking termcolor v1.1.0
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking aho-corasick v0.7.7
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking backtrace v0.3.43
[INFO] [stderr]     Checking regex v1.3.4
[INFO] [stderr]     Checking env_logger v0.6.2
[INFO] [stderr]    Compiling synstructure v0.12.3
[INFO] [stderr]     Checking failure v0.1.6
[INFO] [stderr]     Checking socket-programing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.84s
[INFO] running `Command { std: "docker" "inspect" "5dcba900df145db58eaf284b8278b20814b6855417b3c764e7904b3f97f3ec5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5dcba900df145db58eaf284b8278b20814b6855417b3c764e7904b3f97f3ec5d", kill_on_drop: false }`
[INFO] [stdout] 5dcba900df145db58eaf284b8278b20814b6855417b3c764e7904b3f97f3ec5d
[INFO] checking modeverv/Rust2020_socket_programing against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmodeverv%2FRust2020_socket_programing" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/modeverv/Rust2020_socket_programing 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/modeverv/Rust2020_socket_programing
[INFO] finished tweaking git repo https://github.com/modeverv/Rust2020_socket_programing
[INFO] tweaked toml for git repo https://github.com/modeverv/Rust2020_socket_programing written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/modeverv/Rust2020_socket_programing 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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 53215d07f72e583856ddc82896982770b32586b932ace9ffab59f57bb914226d
[INFO] running `Command { std: "docker" "start" "-a" "53215d07f72e583856ddc82896982770b32586b932ace9ffab59f57bb914226d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "53215d07f72e583856ddc82896982770b32586b932ace9ffab59f57bb914226d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "53215d07f72e583856ddc82896982770b32586b932ace9ffab59f57bb914226d", kill_on_drop: false }`
[INFO] [stdout] 53215d07f72e583856ddc82896982770b32586b932ace9ffab59f57bb914226d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] e1067c5d5c8a4e238af082e4d748831b60eeebf584d7992d05ada74bcc8cb507
[INFO] running `Command { std: "docker" "start" "-a" "e1067c5d5c8a4e238af082e4d748831b60eeebf584d7992d05ada74bcc8cb507", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling cc v1.0.50
[INFO] [stderr]    Compiling memchr v2.3.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling failure_derive v0.1.6
[INFO] [stderr]     Checking quick-error v1.2.3
[INFO] [stderr]     Checking rustc-demangle v0.1.16
[INFO] [stderr]     Checking regex-syntax v0.6.14
[INFO] [stderr]     Checking termcolor v1.1.0
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking aho-corasick v0.7.7
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking regex v1.3.4
[INFO] [stderr]     Checking backtrace v0.3.43
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/regex-1.3.4/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] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "e1067c5d5c8a4e238af082e4d748831b60eeebf584d7992d05ada74bcc8cb507", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1067c5d5c8a4e238af082e4d748831b60eeebf584d7992d05ada74bcc8cb507", kill_on_drop: false }`
[INFO] [stdout] e1067c5d5c8a4e238af082e4d748831b60eeebf584d7992d05ada74bcc8cb507