[INFO] cloning repository https://github.com/sinclabs/rustlings-practice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sinclabs/rustlings-practice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinclabs%2Frustlings-practice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinclabs%2Frustlings-practice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4c2cf6da755efe02725e05ecc3a303304c10a6da
[INFO] checking sinclabs/rustlings-practice against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinclabs%2Frustlings-practice" "/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/sinclabs/rustlings-practice 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/sinclabs/rustlings-practice
[INFO] finished tweaking git repo https://github.com/sinclabs/rustlings-practice
[INFO] tweaked toml for git repo https://github.com/sinclabs/rustlings-practice written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/sinclabs/rustlings-practice 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 notify v4.0.12
[INFO] [stderr]   Downloaded indicatif v0.9.0
[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] 22785fd54acb73764c1fdcbbe728ff6a657858e08f02b9877c28e9eec44662a3
[INFO] running `Command { std: "docker" "start" "-a" "22785fd54acb73764c1fdcbbe728ff6a657858e08f02b9877c28e9eec44662a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "22785fd54acb73764c1fdcbbe728ff6a657858e08f02b9877c28e9eec44662a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22785fd54acb73764c1fdcbbe728ff6a657858e08f02b9877c28e9eec44662a3", kill_on_drop: false }`
[INFO] [stdout] 22785fd54acb73764c1fdcbbe728ff6a657858e08f02b9877c28e9eec44662a3
[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] 0e2c527223d276cdb87439640c2c33b00e6e9277638219733e18cc9c1630f127
[INFO] running `Command { std: "docker" "start" "-a" "0e2c527223d276cdb87439640c2c33b00e6e9277638219733e18cc9c1630f127", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]    Compiling parking_lot v0.8.0
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking lazy_static v0.2.11
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]     Checking lazycell v1.2.1
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking clicolors-control v0.2.0
[INFO] [stderr]     Checking filetime v0.2.5
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking inotify v0.6.1
[INFO] [stderr]     Checking predicates v1.0.1
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking console v0.7.5
[INFO] [stderr]     Checking console v0.6.2
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking notify v4.0.12
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]     Checking indicatif v0.9.0
[INFO] [stderr]     Checking serde v1.0.92
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v1.4.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.15s
[INFO] running `Command { std: "docker" "inspect" "0e2c527223d276cdb87439640c2c33b00e6e9277638219733e18cc9c1630f127", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0e2c527223d276cdb87439640c2c33b00e6e9277638219733e18cc9c1630f127", kill_on_drop: false }`
[INFO] [stdout] 0e2c527223d276cdb87439640c2c33b00e6e9277638219733e18cc9c1630f127
[INFO] checking sinclabs/rustlings-practice against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsinclabs%2Frustlings-practice" "/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/sinclabs/rustlings-practice 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/sinclabs/rustlings-practice
[INFO] finished tweaking git repo https://github.com/sinclabs/rustlings-practice
[INFO] tweaked toml for git repo https://github.com/sinclabs/rustlings-practice written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/sinclabs/rustlings-practice 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] [stderr]     Blocking waiting for file lock on package cache
[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] b6c87ae4347000125955a15530f3506d2ee1d729283264658fc66bca1d6c21ab
[INFO] running `Command { std: "docker" "start" "-a" "b6c87ae4347000125955a15530f3506d2ee1d729283264658fc66bca1d6c21ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b6c87ae4347000125955a15530f3506d2ee1d729283264658fc66bca1d6c21ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b6c87ae4347000125955a15530f3506d2ee1d729283264658fc66bca1d6c21ab", kill_on_drop: false }`
[INFO] [stdout] b6c87ae4347000125955a15530f3506d2ee1d729283264658fc66bca1d6c21ab
[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] 124e85528cf71bcb5c1f17a823ed3b5fd575bb273ae37e7c95e8f62aefc6b953
[INFO] running `Command { std: "docker" "start" "-a" "124e85528cf71bcb5c1f17a823ed3b5fd575bb273ae37e7c95e8f62aefc6b953", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]    Compiling parking_lot v0.8.0
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking lazy_static v0.2.11
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking clicolors-control v1.0.0
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]     Checking lazycell v1.2.1
[INFO] [stderr]     Checking clicolors-control v0.2.0
[INFO] [stderr]     Checking filetime v0.2.5
[INFO] [stderr]     Checking inotify v0.6.1
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking predicates v1.0.1
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking console v0.7.5
[INFO] [stderr]     Checking console v0.6.2
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking notify v4.0.12
[INFO] [stderr]     Checking indicatif v0.9.0
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]     Checking serde v1.0.92
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v1.4.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.27s
[INFO] running `Command { std: "docker" "inspect" "124e85528cf71bcb5c1f17a823ed3b5fd575bb273ae37e7c95e8f62aefc6b953", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "124e85528cf71bcb5c1f17a823ed3b5fd575bb273ae37e7c95e8f62aefc6b953", kill_on_drop: false }`
[INFO] [stdout] 124e85528cf71bcb5c1f17a823ed3b5fd575bb273ae37e7c95e8f62aefc6b953