[INFO] cloning repository https://github.com/Caruychen/Filler-visualizer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Caruychen/Filler-visualizer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaruychen%2FFiller-visualizer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaruychen%2FFiller-visualizer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 75b7529f0f07da7c021f3e75ef5687d30c75815e
[INFO] checking Caruychen/Filler-visualizer against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCaruychen%2FFiller-visualizer" "/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/Caruychen/Filler-visualizer 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/Caruychen/Filler-visualizer
[INFO] finished tweaking git repo https://github.com/Caruychen/Filler-visualizer
[INFO] tweaked toml for git repo https://github.com/Caruychen/Filler-visualizer written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Caruychen/Filler-visualizer 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 json v0.12.4
[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] f8d5908d4a35a043be4a5a4db74b6f2eb759439c3f05071824ee213bf41460a6
[INFO] running `Command { std: "docker" "start" "-a" "f8d5908d4a35a043be4a5a4db74b6f2eb759439c3f05071824ee213bf41460a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f8d5908d4a35a043be4a5a4db74b6f2eb759439c3f05071824ee213bf41460a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8d5908d4a35a043be4a5a4db74b6f2eb759439c3f05071824ee213bf41460a6", kill_on_drop: false }`
[INFO] [stdout] f8d5908d4a35a043be4a5a4db74b6f2eb759439c3f05071824ee213bf41460a6
[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] a1276c69f5ae338819441d5d04b22fcf0c1a9173c78072951705b14258011767
[INFO] running `Command { std: "docker" "start" "-a" "a1276c69f5ae338819441d5d04b22fcf0c1a9173c78072951705b14258011767", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking json v0.12.4
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]     Checking regex v1.5.5
[INFO] [stderr]     Checking filler v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `json` is imported redundantly
[INFO] [stdout]  --> src/arena.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use json;
[INFO] [stdout]   |     ^^^^ the item `json` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `json` is imported redundantly
[INFO] [stdout]  --> src/arena.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use json;
[INFO] [stdout]   |     ^^^^ the item `json` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` 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 item `json` is imported redundantly
[INFO] [stdout]  --> src/bin/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use json;
[INFO] [stdout]   |     ^^^^ the item `json` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `json` is imported redundantly
[INFO] [stdout]  --> src/bin/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use json;
[INFO] [stdout]   |     ^^^^ the item `json` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` 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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.58s
[INFO] running `Command { std: "docker" "inspect" "a1276c69f5ae338819441d5d04b22fcf0c1a9173c78072951705b14258011767", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a1276c69f5ae338819441d5d04b22fcf0c1a9173c78072951705b14258011767", kill_on_drop: false }`
[INFO] [stdout] a1276c69f5ae338819441d5d04b22fcf0c1a9173c78072951705b14258011767