[INFO] cloning repository https://github.com/LearningOS/learn_rust_rustlings-zqch
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/LearningOS/learn_rust_rustlings-zqch" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-zqch", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-zqch'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d1b5db684f41a69126b9a5f146f3aef03ee039a1
[INFO] checking LearningOS/learn_rust_rustlings-zqch against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-zqch" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/LearningOS/learn_rust_rustlings-zqch 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/LearningOS/learn_rust_rustlings-zqch
[INFO] finished tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-zqch
[INFO] tweaked toml for git repo https://github.com/LearningOS/learn_rust_rustlings-zqch written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/learn_rust_rustlings-zqch 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]      Locking 1 package
[INFO] [stderr]     Updating rustlings v4.7.1 (/workspace/builds/worker-7-tc1/source) -> v4.8.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 1487fd62db2c3a639c878360d2f731b5585c521cf278c0b7ac4b8b415ed76bdc
[INFO] running `Command { std: "docker" "start" "-a" "1487fd62db2c3a639c878360d2f731b5585c521cf278c0b7ac4b8b415ed76bdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1487fd62db2c3a639c878360d2f731b5585c521cf278c0b7ac4b8b415ed76bdc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1487fd62db2c3a639c878360d2f731b5585c521cf278c0b7ac4b8b415ed76bdc", kill_on_drop: false }`
[INFO] [stdout] 1487fd62db2c3a639c878360d2f731b5585c521cf278c0b7ac4b8b415ed76bdc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 90898c28eba6ca487c3fd3c4a6ba88a3dd8599b7cc0705f8b3aad8e7a9c04f00
[INFO] running `Command { std: "docker" "start" "-a" "90898c28eba6ca487c3fd3c4a6ba88a3dd8599b7cc0705f8b3aad8e7a9c04f00", kill_on_drop: false }`
[INFO] [stderr]     Checking rustlings v4.8.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.29s
[INFO] running `Command { std: "docker" "inspect" "90898c28eba6ca487c3fd3c4a6ba88a3dd8599b7cc0705f8b3aad8e7a9c04f00", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "90898c28eba6ca487c3fd3c4a6ba88a3dd8599b7cc0705f8b3aad8e7a9c04f00", kill_on_drop: false }`
[INFO] [stdout] 90898c28eba6ca487c3fd3c4a6ba88a3dd8599b7cc0705f8b3aad8e7a9c04f00
[INFO] checking LearningOS/learn_rust_rustlings-zqch against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-zqch" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/LearningOS/learn_rust_rustlings-zqch 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/LearningOS/learn_rust_rustlings-zqch
[INFO] finished tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-zqch
[INFO] tweaked toml for git repo https://github.com/LearningOS/learn_rust_rustlings-zqch written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/learn_rust_rustlings-zqch 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]      Locking 1 package
[INFO] [stderr]     Updating rustlings v4.7.1 (/workspace/builds/worker-7-tc2/source) -> v4.8.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] ebc6137b6dc48a16456d6d9f647c0422b28281129c521e1b914fbc32380e8abe
[INFO] running `Command { std: "docker" "start" "-a" "ebc6137b6dc48a16456d6d9f647c0422b28281129c521e1b914fbc32380e8abe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ebc6137b6dc48a16456d6d9f647c0422b28281129c521e1b914fbc32380e8abe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ebc6137b6dc48a16456d6d9f647c0422b28281129c521e1b914fbc32380e8abe", kill_on_drop: false }`
[INFO] [stdout] ebc6137b6dc48a16456d6d9f647c0422b28281129c521e1b914fbc32380e8abe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] ab70b15b3a66d28e579f69e221197a7216be31e659f01800f2ac1211edb5e79a
[INFO] running `Command { std: "docker" "start" "-a" "ab70b15b3a66d28e579f69e221197a7216be31e659f01800f2ac1211edb5e79a", kill_on_drop: false }`
[INFO] [stderr]     Checking rustlings v4.8.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.29s
[INFO] running `Command { std: "docker" "inspect" "ab70b15b3a66d28e579f69e221197a7216be31e659f01800f2ac1211edb5e79a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab70b15b3a66d28e579f69e221197a7216be31e659f01800f2ac1211edb5e79a", kill_on_drop: false }`
[INFO] [stdout] ab70b15b3a66d28e579f69e221197a7216be31e659f01800f2ac1211edb5e79a