[INFO] cloning repository https://github.com/LearningOS/learn_rust_rustlings-mgt19888
[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-mgt19888" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-mgt19888", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-mgt19888'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a4408f81c3d51f71bebda2a1523561a09d69450e
[INFO] checking LearningOS/learn_rust_rustlings-mgt19888 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-mgt19888" "/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-mgt19888 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-mgt19888
[INFO] finished tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888
[INFO] tweaked toml for git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888 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] 32ae0bfdb7d37db8afd2bf1c49613e9f087190370db469c5d7528a0de6043a5c
[INFO] running `Command { std: "docker" "start" "-a" "32ae0bfdb7d37db8afd2bf1c49613e9f087190370db469c5d7528a0de6043a5c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "32ae0bfdb7d37db8afd2bf1c49613e9f087190370db469c5d7528a0de6043a5c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "32ae0bfdb7d37db8afd2bf1c49613e9f087190370db469c5d7528a0de6043a5c", kill_on_drop: false }`
[INFO] [stdout] 32ae0bfdb7d37db8afd2bf1c49613e9f087190370db469c5d7528a0de6043a5c
[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] 34d4a243df0ab0b8517ed52bce51af376c69cc4fa36dcd58c494f0d943d2c620
[INFO] running `Command { std: "docker" "start" "-a" "34d4a243df0ab0b8517ed52bce51af376c69cc4fa36dcd58c494f0d943d2c620", kill_on_drop: false }`
[INFO] [stderr]     Checking rustlings v4.8.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.63s
[INFO] running `Command { std: "docker" "inspect" "34d4a243df0ab0b8517ed52bce51af376c69cc4fa36dcd58c494f0d943d2c620", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34d4a243df0ab0b8517ed52bce51af376c69cc4fa36dcd58c494f0d943d2c620", kill_on_drop: false }`
[INFO] [stdout] 34d4a243df0ab0b8517ed52bce51af376c69cc4fa36dcd58c494f0d943d2c620
[INFO] checking LearningOS/learn_rust_rustlings-mgt19888 against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-mgt19888" "/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-mgt19888 on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888
[INFO] finished tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888
[INFO] tweaked toml for git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/learn_rust_rustlings-mgt19888 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "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-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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 77ef7e69cd4b696ec7901f1fad3dff7d12eddf226d0ed034bd1683aa5a8b9e9a
[INFO] running `Command { std: "docker" "start" "-a" "77ef7e69cd4b696ec7901f1fad3dff7d12eddf226d0ed034bd1683aa5a8b9e9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "77ef7e69cd4b696ec7901f1fad3dff7d12eddf226d0ed034bd1683aa5a8b9e9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77ef7e69cd4b696ec7901f1fad3dff7d12eddf226d0ed034bd1683aa5a8b9e9a", kill_on_drop: false }`
[INFO] [stdout] 77ef7e69cd4b696ec7901f1fad3dff7d12eddf226d0ed034bd1683aa5a8b9e9a
[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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ac6523bad9b7e59de0ffacef1df0b345a7081e42129b36197c951561b4fafbd7
[INFO] running `Command { std: "docker" "start" "-a" "ac6523bad9b7e59de0ffacef1df0b345a7081e42129b36197c951561b4fafbd7", kill_on_drop: false }`
[INFO] [stderr]     Checking rustlings v4.8.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.88s
[INFO] running `Command { std: "docker" "inspect" "ac6523bad9b7e59de0ffacef1df0b345a7081e42129b36197c951561b4fafbd7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac6523bad9b7e59de0ffacef1df0b345a7081e42129b36197c951561b4fafbd7", kill_on_drop: false }`
[INFO] [stdout] ac6523bad9b7e59de0ffacef1df0b345a7081e42129b36197c951561b4fafbd7