[INFO] crate persistent_rope 0.1.2 is already in cache
[INFO] testing persistent_rope-0.1.2 against 1.44.0 for beta-1.45-1
[INFO] extracting crate persistent_rope 0.1.2 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate persistent_rope 0.1.2 on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate persistent_rope 0.1.2
[INFO] finished tweaking crates.io crate persistent_rope 0.1.2
[INFO] tweaked toml for crates.io crate persistent_rope 0.1.2 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] adae34d9d21cf44739f3264435b338d9f25c1352b017c443558de47d6bbf957b
[INFO] running `"docker" "start" "-a" "adae34d9d21cf44739f3264435b338d9f25c1352b017c443558de47d6bbf957b"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling persistent_rope v0.1.2 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0432]: unresolved import `alloc::arc`
[INFO] [stderr]  --> src/rope.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | use alloc::arc::Arc;
[INFO] [stderr]   |            ^^^ could not find `arc` in `alloc`
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(alloc)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0119]: conflicting implementations of trait `core::ops::Add<char>` for type `rope::Rope`:
[INFO] [stderr]    --> src/rope.rs:617:1
[INFO] [stderr]     |
[INFO] [stderr] 578 | / impl<T> Add<T> for Rope
[INFO] [stderr] 579 | | where
[INFO] [stderr] 580 | |     T: Into<Rope>,
[INFO] [stderr] 581 | | {
[INFO] [stderr] ...   |
[INFO] [stderr] 594 | |     }
[INFO] [stderr] 595 | | }
[INFO] [stderr]     | |_- first implementation here
[INFO] [stderr] ...
[INFO] [stderr] 617 |   impl Add<char> for Rope {
[INFO] [stderr]     |   ^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `rope::Rope`
[INFO] [stderr] 
[INFO] [stderr] error[E0119]: conflicting implementations of trait `core::ops::Add<char>` for type `&rope::Rope`:
[INFO] [stderr]    --> src/rope.rs:631:1
[INFO] [stderr]     |
[INFO] [stderr] 597 | / impl<'a, T> Add<T> for &'a Rope
[INFO] [stderr] 598 | | where
[INFO] [stderr] 599 | |     T: Into<Rope>,
[INFO] [stderr] 600 | | {
[INFO] [stderr] ...   |
[INFO] [stderr] 614 | |     }
[INFO] [stderr] 615 | | }
[INFO] [stderr]     | |_- first implementation here
[INFO] [stderr] ...
[INFO] [stderr] 631 |   impl<'a> Add<char> for &'a Rope {
[INFO] [stderr]     |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `&rope::Rope`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0119, E0432, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0119`.
[INFO] [stderr] error: could not compile `persistent_rope`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "adae34d9d21cf44739f3264435b338d9f25c1352b017c443558de47d6bbf957b"`
[INFO] running `"docker" "rm" "-f" "adae34d9d21cf44739f3264435b338d9f25c1352b017c443558de47d6bbf957b"`
[INFO] [stdout] adae34d9d21cf44739f3264435b338d9f25c1352b017c443558de47d6bbf957b