[INFO] cloning repository https://github.com/zjhken/MioPractice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zjhken/MioPractice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b7e077633c9c64e7342ee2e473eea1a4421e8a49
[INFO] checking zjhken/MioPractice against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice" "/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/zjhken/MioPractice 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/zjhken/MioPractice
[INFO] finished tweaking git repo https://github.com/zjhken/MioPractice
[INFO] tweaked toml for git repo https://github.com/zjhken/MioPractice written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/zjhken/MioPractice 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 log v0.4.4
[INFO] [stderr]   Downloaded cfg-if v0.1.3
[INFO] [stderr]   Downloaded net2 v0.2.32
[INFO] [stderr]   Downloaded simple_logger v0.5.0
[INFO] [stderr]   Downloaded libc v0.2.42
[INFO] [stderr]   Downloaded mio v0.6.14
[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] 835247298c93c0ae50954c8496999c9cb4cb4b40133a2a4ac1fdcf6e4db03ca8
[INFO] running `Command { std: "docker" "start" "-a" "835247298c93c0ae50954c8496999c9cb4cb4b40133a2a4ac1fdcf6e4db03ca8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "835247298c93c0ae50954c8496999c9cb4cb4b40133a2a4ac1fdcf6e4db03ca8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "835247298c93c0ae50954c8496999c9cb4cb4b40133a2a4ac1fdcf6e4db03ca8", kill_on_drop: false }`
[INFO] [stdout] 835247298c93c0ae50954c8496999c9cb4cb4b40133a2a4ac1fdcf6e4db03ca8
[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] f40367a5d0777322f3d37571a9ee1c41b4cdf053699d8d6c3beafb5784faa3ee
[INFO] running `Command { std: "docker" "start" "-a" "f40367a5d0777322f3d37571a9ee1c41b4cdf053699d8d6c3beafb5784faa3ee", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]     Checking cfg-if v0.1.3
[INFO] [stderr]     Checking slab v0.4.0
[INFO] [stderr]     Checking lazycell v0.6.0
[INFO] [stderr]     Checking log v0.4.4
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking net2 v0.2.32
[INFO] [stderr]     Checking mio v0.6.14
[INFO] [stderr]     Checking simple_logger v0.5.0
[INFO] [stderr]     Checking MioPractice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `nll` has been stable since 1.63.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(nll)]
[INFO] [stdout]   |            ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `nll` has been stable since 1.63.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(nll)]
[INFO] [stdout]   |            ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `nll` has been stable since 1.63.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> tests/IntegrationTest.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(nll)]
[INFO] [stdout]   |            ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` 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 0.72s
[INFO] running `Command { std: "docker" "inspect" "f40367a5d0777322f3d37571a9ee1c41b4cdf053699d8d6c3beafb5784faa3ee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f40367a5d0777322f3d37571a9ee1c41b4cdf053699d8d6c3beafb5784faa3ee", kill_on_drop: false }`
[INFO] [stdout] f40367a5d0777322f3d37571a9ee1c41b4cdf053699d8d6c3beafb5784faa3ee
[INFO] checking zjhken/MioPractice against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzjhken%2FMioPractice" "/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/zjhken/MioPractice 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/zjhken/MioPractice
[INFO] finished tweaking git repo https://github.com/zjhken/MioPractice
[INFO] tweaked toml for git repo https://github.com/zjhken/MioPractice written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/zjhken/MioPractice 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] bcdcb33c64c48c0e653eb054d9dff92f2df35a70b650e49f661e6e185a503411
[INFO] running `Command { std: "docker" "start" "-a" "bcdcb33c64c48c0e653eb054d9dff92f2df35a70b650e49f661e6e185a503411", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bcdcb33c64c48c0e653eb054d9dff92f2df35a70b650e49f661e6e185a503411", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bcdcb33c64c48c0e653eb054d9dff92f2df35a70b650e49f661e6e185a503411", kill_on_drop: false }`
[INFO] [stdout] bcdcb33c64c48c0e653eb054d9dff92f2df35a70b650e49f661e6e185a503411
[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] cc70ff9fabdf27c073e84a1335f855b1e366ebb29c6c2147c89a45fc4b65cfc4
[INFO] running `Command { std: "docker" "start" "-a" "cc70ff9fabdf27c073e84a1335f855b1e366ebb29c6c2147c89a45fc4b65cfc4", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]     Checking cfg-if v0.1.3
[INFO] [stderr]     Checking slab v0.4.0
[INFO] [stderr]     Checking lazycell v0.6.0
[INFO] [stderr]     Checking log v0.4.4
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking net2 v0.2.32
[INFO] [stderr]     Checking mio v0.6.14
[INFO] [stderr]     Checking simple_logger v0.5.0
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]     --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/mio-0.6.14/src/poll.rs:2065:13
[INFO] [stdout]      |
[INFO] [stdout] 2065 |             panic!();
[INFO] [stdout]      |             ^^^^^^^^ cannot infer type
[INFO] [stdout]      |
[INFO] [stdout]      = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
[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 `mio` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "cc70ff9fabdf27c073e84a1335f855b1e366ebb29c6c2147c89a45fc4b65cfc4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cc70ff9fabdf27c073e84a1335f855b1e366ebb29c6c2147c89a45fc4b65cfc4", kill_on_drop: false }`
[INFO] [stdout] cc70ff9fabdf27c073e84a1335f855b1e366ebb29c6c2147c89a45fc4b65cfc4