[INFO] fetching crate zettel-core 0.2.0...
[INFO] testing zettel-core-0.2.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate zettel-core 0.2.0 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate zettel-core 0.2.0
[INFO] finished tweaking crates.io crate zettel-core 0.2.0
[INFO] tweaked toml for crates.io crate zettel-core 0.2.0 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate zettel-core 0.2.0 on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate zettel-core 0.2.0 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" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 39d3e1fbf6d52ca956cf79a1591cef273a27623ea25efecf4a1d1d419560976b
[INFO] running `Command { std: "docker" "start" "-a" "39d3e1fbf6d52ca956cf79a1591cef273a27623ea25efecf4a1d1d419560976b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "39d3e1fbf6d52ca956cf79a1591cef273a27623ea25efecf4a1d1d419560976b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39d3e1fbf6d52ca956cf79a1591cef273a27623ea25efecf4a1d1d419560976b", kill_on_drop: false }`
[INFO] [stdout] 39d3e1fbf6d52ca956cf79a1591cef273a27623ea25efecf4a1d1d419560976b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 42c16e6364fa95e23e335f43dda90f3d8934d822ed741e858f2020f59597bc04
[INFO] running `Command { std: "docker" "start" "-a" "42c16e6364fa95e23e335f43dda90f3d8934d822ed741e858f2020f59597bc04", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling hashbrown v0.15.5
[INFO] [stderr]    Compiling winnow v0.7.12
[INFO] [stderr]    Compiling aho-corasick v1.1.3
[INFO] [stderr]    Compiling dirs-sys v0.4.1
[INFO] [stderr]    Compiling dirs v5.0.1
[INFO] [stderr]    Compiling indexmap v2.10.0
[INFO] [stderr]    Compiling regex-automata v0.4.9
[INFO] [stderr]    Compiling serde_derive v1.0.219
[INFO] [stderr]    Compiling thiserror-impl v1.0.69
[INFO] [stderr]    Compiling thiserror v1.0.69
[INFO] [stderr]    Compiling regex v1.11.1
[INFO] [stderr]    Compiling serde v1.0.219
[INFO] [stderr]    Compiling serde_spanned v0.6.9
[INFO] [stderr]    Compiling toml_datetime v0.6.11
[INFO] [stderr]    Compiling toml_edit v0.22.27
[INFO] [stderr]    Compiling toml v0.8.23
[INFO] [stderr]    Compiling zettel-core v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 14.02s
[INFO] running `Command { std: "docker" "inspect" "42c16e6364fa95e23e335f43dda90f3d8934d822ed741e858f2020f59597bc04", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42c16e6364fa95e23e335f43dda90f3d8934d822ed741e858f2020f59597bc04", kill_on_drop: false }`
[INFO] [stdout] 42c16e6364fa95e23e335f43dda90f3d8934d822ed741e858f2020f59597bc04
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dd6cefd1bdde2280f52f8485f74ce4751efe2012a83e0eee885afe0d0be21390
[INFO] running `Command { std: "docker" "start" "-a" "dd6cefd1bdde2280f52f8485f74ce4751efe2012a83e0eee885afe0d0be21390", kill_on_drop: false }`
[INFO] [stderr]    Compiling zettel-core v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0502]: cannot borrow `existing_ids` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/id.rs:813:9
[INFO] [stdout]     |
[INFO] [stdout] 801 |         let manager = IdManager::new(config, |id: &str| existing_ids.contains(id));
[INFO] [stdout]     |                                              ---------- ------------ first borrow occurs due to use of `existing_ids` in closure
[INFO] [stdout]     |                                              |
[INFO] [stdout]     |                                              immutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 813 |         existing_ids.insert("1b".to_string());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] 814 |         existing_ids.insert("1c".to_string());
[INFO] [stdout] 815 |         let next_child = manager.next_available_child(&current);
[INFO] [stdout]     |                          ------- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0502]: cannot borrow `existing_ids` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/id.rs:814:9
[INFO] [stdout]     |
[INFO] [stdout] 801 |         let manager = IdManager::new(config, |id: &str| existing_ids.contains(id));
[INFO] [stdout]     |                                              ---------- ------------ first borrow occurs due to use of `existing_ids` in closure
[INFO] [stdout]     |                                              |
[INFO] [stdout]     |                                              immutable borrow occurs here
[INFO] [stdout] ...
[INFO] [stdout] 814 |         existing_ids.insert("1c".to_string());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] 815 |         let next_child = manager.next_available_child(&current);
[INFO] [stdout]     |                          ------- immutable borrow later used here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0502`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `zettel-core` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "dd6cefd1bdde2280f52f8485f74ce4751efe2012a83e0eee885afe0d0be21390", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd6cefd1bdde2280f52f8485f74ce4751efe2012a83e0eee885afe0d0be21390", kill_on_drop: false }`
[INFO] [stdout] dd6cefd1bdde2280f52f8485f74ce4751efe2012a83e0eee885afe0d0be21390
