[INFO] cloning repository https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao [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-RustaceanLao" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-RustaceanLao", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-RustaceanLao'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 1b7fb686f1e39fd99920cda1922cfcae6e530ea2 [INFO] checking LearningOS/learn_rust_rustlings-RustaceanLao against try#c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f for 2025-12-16-next-solver-global [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Flearn_rust_rustlings-RustaceanLao" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao [INFO] finished tweaking git repo https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao [INFO] tweaked toml for git repo https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao written to /workspace/builds/worker-7-tc2/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao on toolchain c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/LearningOS/learn_rust_rustlings-RustaceanLao 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" "+c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Downloading crates ... [INFO] [stderr] Downloaded home v0.5.3 [INFO] [stderr] Downloaded argh v0.1.5 [INFO] [stderr] Downloaded predicates-core v1.0.2 [INFO] [stderr] Downloaded argh_shared v0.1.5 [INFO] [stderr] Downloaded predicates-tree v1.0.3 [INFO] [stderr] Downloaded argh_derive v0.1.5 [INFO] [stderr] Downloaded serde v1.0.129 [INFO] [stderr] Downloaded serde_derive v1.0.129 [INFO] [stderr] Downloaded syn v1.0.75 [INFO] [stderr] Downloaded libc v0.2.100 [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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 78a963b2dc2d94997905216e3a7aac97668268a17b63d3a5b91d005ebf0ecd99 [INFO] running `Command { std: "docker" "start" "-a" "78a963b2dc2d94997905216e3a7aac97668268a17b63d3a5b91d005ebf0ecd99", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "78a963b2dc2d94997905216e3a7aac97668268a17b63d3a5b91d005ebf0ecd99", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "78a963b2dc2d94997905216e3a7aac97668268a17b63d3a5b91d005ebf0ecd99", kill_on_drop: false }` [INFO] [stdout] 78a963b2dc2d94997905216e3a7aac97668268a17b63d3a5b91d005ebf0ecd99 [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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+c9557a20e5ef2e0e02c29a5fafd850d1b7cf1e4f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 92b353995df098f37d255fafcfc55afe20020bc41318490063ea9788387e465f [INFO] running `Command { std: "docker" "start" "-a" "92b353995df098f37d255fafcfc55afe20020bc41318490063ea9788387e465f", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.100 [INFO] [stderr] Compiling syn v1.0.75 [INFO] [stderr] Compiling serde_derive v1.0.129 [INFO] [stderr] Compiling serde v1.0.129 [INFO] [stderr] Compiling serde_json v1.0.81 [INFO] [stderr] Checking itoa v1.0.2 [INFO] [stderr] Checking lazycell v1.3.0 [INFO] [stderr] Checking once_cell v1.10.0 [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 regex v1.5.5 [INFO] [stderr] Checking float-cmp v0.8.0 [INFO] [stderr] Checking difference v2.0.0 [INFO] [stderr] Checking home v0.5.3 [INFO] [stderr] Checking treeline v0.1.0 [INFO] [stderr] Checking glob v0.3.0 [INFO] [stderr] Checking predicates-tree v1.0.3 [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 filetime v0.2.15 [INFO] [stderr] Checking inotify v0.7.1 [INFO] [stderr] Checking console v0.15.0 [INFO] [stderr] Checking predicates v1.0.8 [INFO] [stderr] Checking mio v0.6.23 [INFO] [stderr] Checking indicatif v0.16.2 [INFO] [stderr] Checking mio-extras v2.0.6 [INFO] [stderr] Compiling argh_derive v0.1.5 [INFO] [stderr] Checking notify v4.0.17 [INFO] [stderr] Checking argh v0.1.5 [INFO] [stderr] Checking toml v0.5.9 [INFO] [stderr] Checking rustlings v4.8.0 (/opt/rustwide/workdir) [INFO] [stderr] Checking assert_cmd v0.11.1 [INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing [INFO] [stdout] --> src/exercise.rs:109:20 [INFO] [stdout] | [INFO] [stdout] 109 | pub fn compile(&self) -> Result { [INFO] [stdout] | ^^^^^ ^^^^^^^^^^^^^^^^ the same lifetime is hidden here [INFO] [stdout] | | [INFO] [stdout] | the lifetime is elided here [INFO] [stdout] | [INFO] [stdout] = help: the same lifetime is referred to in inconsistent ways, making the signature confusing [INFO] [stdout] = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default [INFO] [stdout] help: use `'_` for type paths [INFO] [stdout] | [INFO] [stdout] 109 | pub fn compile(&self) -> Result, ExerciseOutput> { [INFO] [stdout] | ++++ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing [INFO] [stdout] --> src/exercise.rs:109:20 [INFO] [stdout] | [INFO] [stdout] 109 | pub fn compile(&self) -> Result { [INFO] [stdout] | ^^^^^ ^^^^^^^^^^^^^^^^ the same lifetime is hidden here [INFO] [stdout] | | [INFO] [stdout] | the lifetime is elided here [INFO] [stdout] | [INFO] [stdout] = help: the same lifetime is referred to in inconsistent ways, making the signature confusing [INFO] [stdout] = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default [INFO] [stdout] help: use `'_` for type paths [INFO] [stdout] | [INFO] [stdout] 109 | pub fn compile(&self) -> Result, ExerciseOutput> { [INFO] [stdout] | ++++ [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 16.13s [INFO] running `Command { std: "docker" "inspect" "92b353995df098f37d255fafcfc55afe20020bc41318490063ea9788387e465f", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "92b353995df098f37d255fafcfc55afe20020bc41318490063ea9788387e465f", kill_on_drop: false }` [INFO] [stdout] 92b353995df098f37d255fafcfc55afe20020bc41318490063ea9788387e465f