[INFO] cloning repository https://github.com/fx2y/learn-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fx2y/learn-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffx2y%2Flearn-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffx2y%2Flearn-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] feda104a0d1a2e11969e1318d3da7fbf74e213af
[INFO] checking fx2y/learn-rust against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffx2y%2Flearn-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/fx2y/learn-rust on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/fx2y/learn-rust
[INFO] finished tweaking git repo https://github.com/fx2y/learn-rust
[INFO] tweaked toml for git repo https://github.com/fx2y/learn-rust written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/fx2y/learn-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded crossterm v0.16.0
[INFO] [stderr]   Downloaded crossbeam-channel v0.4.2
[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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 21ea0522bdc5231d3dd0c83b16af284d773ae250bc7a0c0677f1defea69a50b0
[INFO] running `Command { std: "docker" "start" "-a" "21ea0522bdc5231d3dd0c83b16af284d773ae250bc7a0c0677f1defea69a50b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "21ea0522bdc5231d3dd0c83b16af284d773ae250bc7a0c0677f1defea69a50b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21ea0522bdc5231d3dd0c83b16af284d773ae250bc7a0c0677f1defea69a50b0", kill_on_drop: false }`
[INFO] [stdout] 21ea0522bdc5231d3dd0c83b16af284d773ae250bc7a0c0677f1defea69a50b0
[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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 84e2e943b6084a6908b271a8a17fc81476b064d0369e996bb767e4d4e54ffe3c
[INFO] running `Command { std: "docker" "start" "-a" "84e2e943b6084a6908b271a8a17fc81476b064d0369e996bb767e4d4e54ffe3c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking arc-swap v0.4.4
[INFO] [stderr]     Checking smallvec v1.2.0
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking lock_api v0.3.3
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking parking_lot_core v0.7.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking crossbeam-channel v0.4.2
[INFO] [stderr]     Checking crossbeam-queue v0.2.1
[INFO] [stderr]     Checking parking_lot v0.10.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking crossbeam v0.7.3
[INFO] [stderr]     Checking signal-hook v0.1.13
[INFO] [stderr]     Checking crossterm v0.16.0
[INFO] [stderr]     Checking pipeviewer v0.1.0 (/opt/rustwide/workdir/pipeviewer)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 9.91s
[INFO] running `Command { std: "docker" "inspect" "84e2e943b6084a6908b271a8a17fc81476b064d0369e996bb767e4d4e54ffe3c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84e2e943b6084a6908b271a8a17fc81476b064d0369e996bb767e4d4e54ffe3c", kill_on_drop: false }`
[INFO] [stdout] 84e2e943b6084a6908b271a8a17fc81476b064d0369e996bb767e4d4e54ffe3c
[INFO] checking fx2y/learn-rust against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffx2y%2Flearn-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/fx2y/learn-rust on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/fx2y/learn-rust
[INFO] finished tweaking git repo https://github.com/fx2y/learn-rust
[INFO] tweaked toml for git repo https://github.com/fx2y/learn-rust written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/fx2y/learn-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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 39ae1176774ba22ad45c87770e2871bc260e7f0cc899b4001e6bef7c8f885d41
[INFO] running `Command { std: "docker" "start" "-a" "39ae1176774ba22ad45c87770e2871bc260e7f0cc899b4001e6bef7c8f885d41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "39ae1176774ba22ad45c87770e2871bc260e7f0cc899b4001e6bef7c8f885d41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39ae1176774ba22ad45c87770e2871bc260e7f0cc899b4001e6bef7c8f885d41", kill_on_drop: false }`
[INFO] [stdout] 39ae1176774ba22ad45c87770e2871bc260e7f0cc899b4001e6bef7c8f885d41
[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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] de674af42ea09f1469f700b799555f6a8cd54e77c0493d9626753c9ec798ad99
[INFO] running `Command { std: "docker" "start" "-a" "de674af42ea09f1469f700b799555f6a8cd54e77c0493d9626753c9ec798ad99", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking arc-swap v0.4.4
[INFO] [stderr]     Checking smallvec v1.2.0
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking lock_api v0.3.3
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]     Checking crossbeam-queue v0.2.1
[INFO] [stderr]     Checking crossbeam-channel v0.4.2
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]     Checking parking_lot_core v0.7.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking parking_lot v0.10.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking crossbeam v0.7.3
[INFO] [stderr]     Checking signal-hook v0.1.13
[INFO] [stderr]     Checking crossterm v0.16.0
[INFO] [stderr]     Checking pipeviewer v0.1.0 (/opt/rustwide/workdir/pipeviewer)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.10s
[INFO] running `Command { std: "docker" "inspect" "de674af42ea09f1469f700b799555f6a8cd54e77c0493d9626753c9ec798ad99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "de674af42ea09f1469f700b799555f6a8cd54e77c0493d9626753c9ec798ad99", kill_on_drop: false }`
[INFO] [stdout] de674af42ea09f1469f700b799555f6a8cd54e77c0493d9626753c9ec798ad99