[INFO] cloning repository https://github.com/zsx2034/rustlins_exercise_answer [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zsx2034/rustlins_exercise_answer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzsx2034%2Frustlins_exercise_answer", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzsx2034%2Frustlins_exercise_answer'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 3ca92493e23804dc72ccc5db30cf4f58fa0116d8 [INFO] checking zsx2034/rustlins_exercise_answer against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzsx2034%2Frustlins_exercise_answer" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/zsx2034/rustlins_exercise_answer 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/zsx2034/rustlins_exercise_answer [INFO] finished tweaking git repo https://github.com/zsx2034/rustlins_exercise_answer [INFO] tweaked toml for git repo https://github.com/zsx2034/rustlins_exercise_answer written to /workspace/builds/worker-2-tc1/source/Cargo.toml [INFO] crate git repo https://github.com/zsx2034/rustlins_exercise_answer 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 8c8360b34cdd4405181210a964f2754f71e447e60a677a09385f6a883a33779d [INFO] running `Command { std: "docker" "start" "-a" "8c8360b34cdd4405181210a964f2754f71e447e60a677a09385f6a883a33779d", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "8c8360b34cdd4405181210a964f2754f71e447e60a677a09385f6a883a33779d", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "8c8360b34cdd4405181210a964f2754f71e447e60a677a09385f6a883a33779d", kill_on_drop: false }` [INFO] [stdout] 8c8360b34cdd4405181210a964f2754f71e447e60a677a09385f6a883a33779d [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] d1c611218a56cbe33ac926988dd7cdb74726a18eb70b97dbe5e79a813de121fc [INFO] running `Command { std: "docker" "start" "-a" "d1c611218a56cbe33ac926988dd7cdb74726a18eb70b97dbe5e79a813de121fc", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.100 [INFO] [stderr] Compiling proc-macro2 v1.0.28 [INFO] [stderr] Compiling syn v1.0.75 [INFO] [stderr] Compiling autocfg v1.0.1 [INFO] [stderr] Compiling log v0.4.14 [INFO] [stderr] Compiling serde_derive v1.0.129 [INFO] [stderr] Checking regex-syntax v0.6.25 [INFO] [stderr] Compiling serde v1.0.129 [INFO] [stderr] Checking cfg-if v0.1.10 [INFO] [stderr] Checking scopeguard v1.1.0 [INFO] [stderr] Compiling ryu v1.0.5 [INFO] [stderr] Checking smallvec v1.6.1 [INFO] [stderr] Checking instant v0.1.10 [INFO] [stderr] Checking slab v0.4.4 [INFO] [stderr] Compiling unicode-segmentation v1.8.0 [INFO] [stderr] Checking aho-corasick v0.7.18 [INFO] [stderr] Compiling serde_json v1.0.66 [INFO] [stderr] Checking unicode-width v0.1.8 [INFO] [stderr] Checking lock_api v0.4.4 [INFO] [stderr] Checking lazycell v1.3.0 [INFO] [stderr] Checking same-file v1.0.6 [INFO] [stderr] Checking itoa v0.4.8 [INFO] [stderr] Checking predicates-core v1.0.2 [INFO] [stderr] Compiling escargot v0.4.0 [INFO] [stderr] Compiling argh_shared v0.1.5 [INFO] [stderr] Checking walkdir v2.3.2 [INFO] [stderr] Checking normalize-line-endings v0.3.0 [INFO] [stderr] Compiling heck v0.3.3 [INFO] [stderr] Checking difference v2.0.0 [INFO] [stderr] Checking treeline v0.1.0 [INFO] [stderr] Compiling num-traits v0.2.14 [INFO] [stderr] Checking glob v0.3.0 [INFO] [stderr] Checking predicates-tree v1.0.3 [INFO] [stderr] Compiling quote v1.0.9 [INFO] [stderr] Checking parking_lot_core v0.8.3 [INFO] [stderr] Checking net2 v0.2.37 [INFO] [stderr] Checking iovec v0.1.4 [INFO] [stderr] Checking terminal_size v0.1.17 [INFO] [stderr] Checking inotify-sys v0.1.5 [INFO] [stderr] Checking termios v0.3.3 [INFO] [stderr] Checking clicolors-control v1.0.1 [INFO] [stderr] Checking atty v0.2.14 [INFO] [stderr] Checking filetime v0.2.15 [INFO] [stderr] Checking inotify v0.7.1 [INFO] [stderr] Checking parking_lot v0.11.1 [INFO] [stderr] Checking mio v0.6.23 [INFO] [stderr] Checking number_prefix v0.2.8 [INFO] [stderr] Checking float-cmp v0.8.0 [INFO] [stderr] Checking mio-extras v2.0.6 [INFO] [stderr] Checking notify v4.0.17 [INFO] [stderr] Checking regex v1.5.4 [INFO] [stderr] Checking console v0.14.1 [INFO] [stderr] Checking console v0.7.7 [INFO] [stderr] Checking predicates v1.0.8 [INFO] [stderr] Compiling argh_derive v0.1.5 [INFO] [stderr] Checking indicatif v0.10.3 [INFO] [stderr] Checking argh v0.1.5 [INFO] [stderr] Checking toml v0.4.10 [INFO] [stderr] Checking rustlings v4.6.0 (/opt/rustwide/workdir) [INFO] [stderr] Checking assert_cmd v0.11.1 [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 19.44s [INFO] running `Command { std: "docker" "inspect" "d1c611218a56cbe33ac926988dd7cdb74726a18eb70b97dbe5e79a813de121fc", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "d1c611218a56cbe33ac926988dd7cdb74726a18eb70b97dbe5e79a813de121fc", kill_on_drop: false }` [INFO] [stdout] d1c611218a56cbe33ac926988dd7cdb74726a18eb70b97dbe5e79a813de121fc [INFO] checking zsx2034/rustlins_exercise_answer against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzsx2034%2Frustlins_exercise_answer" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/zsx2034/rustlins_exercise_answer 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/zsx2034/rustlins_exercise_answer [INFO] finished tweaking git repo https://github.com/zsx2034/rustlins_exercise_answer [INFO] tweaked toml for git repo https://github.com/zsx2034/rustlins_exercise_answer written to /workspace/builds/worker-2-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/zsx2034/rustlins_exercise_answer 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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 50a059a4b3e991d1892b7523b6a2f385a5007cdeec49e8a6955b572eca75a9d3 [INFO] running `Command { std: "docker" "start" "-a" "50a059a4b3e991d1892b7523b6a2f385a5007cdeec49e8a6955b572eca75a9d3", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "50a059a4b3e991d1892b7523b6a2f385a5007cdeec49e8a6955b572eca75a9d3", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "50a059a4b3e991d1892b7523b6a2f385a5007cdeec49e8a6955b572eca75a9d3", kill_on_drop: false }` [INFO] [stdout] 50a059a4b3e991d1892b7523b6a2f385a5007cdeec49e8a6955b572eca75a9d3 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 6044c6a5a229283255a637ec050ce83535fcf1ef994f30f94fe62a29c94d6843 [INFO] running `Command { std: "docker" "start" "-a" "6044c6a5a229283255a637ec050ce83535fcf1ef994f30f94fe62a29c94d6843", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.100 [INFO] [stderr] Compiling proc-macro2 v1.0.28 [INFO] [stderr] Compiling syn v1.0.75 [INFO] [stderr] Compiling autocfg v1.0.1 [INFO] [stderr] Compiling serde_derive v1.0.129 [INFO] [stderr] Compiling log v0.4.14 [INFO] [stderr] Compiling serde v1.0.129 [INFO] [stderr] Checking regex-syntax v0.6.25 [INFO] [stderr] Checking scopeguard v1.1.0 [INFO] [stderr] Checking smallvec v1.6.1 [INFO] [stderr] Checking cfg-if v0.1.10 [INFO] [stderr] Compiling ryu v1.0.5 [INFO] [stderr] Checking instant v0.1.10 [INFO] [stderr] Compiling unicode-segmentation v1.8.0 [INFO] [stderr] Checking unicode-width v0.1.8 [INFO] [stderr] Checking aho-corasick v0.7.18 [INFO] [stderr] Checking slab v0.4.4 [INFO] [stderr] Compiling serde_json v1.0.66 [INFO] [stderr] Checking lock_api v0.4.4 [INFO] [stderr] Checking itoa v0.4.8 [INFO] [stderr] Checking lazycell v1.3.0 [INFO] [stderr] Checking same-file v1.0.6 [INFO] [stderr] Compiling argh_shared v0.1.5 [INFO] [stderr] Compiling escargot v0.4.0 [INFO] [stderr] Checking predicates-core v1.0.2 [INFO] [stderr] Checking walkdir v2.3.2 [INFO] [stderr] Compiling num-traits v0.2.14 [INFO] [stderr] Checking normalize-line-endings v0.3.0 [INFO] [stderr] Checking difference v2.0.0 [INFO] [stderr] Checking treeline v0.1.0 [INFO] [stderr] Checking glob v0.3.0 [INFO] [stderr] Compiling heck v0.3.3 [INFO] [stderr] Checking predicates-tree v1.0.3 [INFO] [stderr] Compiling quote v1.0.9 [INFO] [stderr] Checking iovec v0.1.4 [INFO] [stderr] Checking parking_lot_core v0.8.3 [INFO] [stderr] Checking net2 v0.2.37 [INFO] [stderr] Checking terminal_size v0.1.17 [INFO] [stderr] Checking inotify-sys v0.1.5 [INFO] [stderr] Checking clicolors-control v1.0.1 [INFO] [stderr] Checking atty v0.2.14 [INFO] [stderr] Checking filetime v0.2.15 [INFO] [stderr] Checking termios v0.3.3 [INFO] [stderr] Checking inotify v0.7.1 [INFO] [stderr] Checking parking_lot v0.11.1 [INFO] [stderr] Checking mio v0.6.23 [INFO] [stderr] Checking float-cmp v0.8.0 [INFO] [stderr] Checking number_prefix v0.2.8 [INFO] [stderr] Checking regex v1.5.4 [INFO] [stderr] Checking mio-extras v2.0.6 [INFO] [stderr] Checking notify v4.0.17 [INFO] [stderr] Checking console v0.14.1 [INFO] [stderr] Checking predicates v1.0.8 [INFO] [stderr] Checking console v0.7.7 [INFO] [stderr] Checking indicatif v0.10.3 [INFO] [stderr] Compiling argh_derive v0.1.5 [INFO] [stderr] Checking argh v0.1.5 [INFO] [stderr] Checking toml v0.4.10 [INFO] [stderr] Checking rustlings v4.6.0 (/opt/rustwide/workdir) [INFO] [stderr] Checking assert_cmd v0.11.1 [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 14.06s [INFO] running `Command { std: "docker" "inspect" "6044c6a5a229283255a637ec050ce83535fcf1ef994f30f94fe62a29c94d6843", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "6044c6a5a229283255a637ec050ce83535fcf1ef994f30f94fe62a29c94d6843", kill_on_drop: false }` [INFO] [stdout] 6044c6a5a229283255a637ec050ce83535fcf1ef994f30f94fe62a29c94d6843