[INFO] fetching crate exist 0.1.2...
[INFO] testing exist-0.1.2 against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409
[INFO] extracting crate exist 0.1.2 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate exist 0.1.2 on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate exist 0.1.2
[INFO] finished tweaking crates.io crate exist 0.1.2
[INFO] tweaked toml for crates.io crate exist 0.1.2 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] b8dc526f6742da2c20d3a74a6ee7e423e0448c7645d1614a63d84eaf92cb15c8
[INFO] running `Command { std: "docker" "start" "-a" "b8dc526f6742da2c20d3a74a6ee7e423e0448c7645d1614a63d84eaf92cb15c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b8dc526f6742da2c20d3a74a6ee7e423e0448c7645d1614a63d84eaf92cb15c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8dc526f6742da2c20d3a74a6ee7e423e0448c7645d1614a63d84eaf92cb15c8", kill_on_drop: false }`
[INFO] [stdout] b8dc526f6742da2c20d3a74a6ee7e423e0448c7645d1614a63d84eaf92cb15c8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 529474d797ba7edae0b17555519a3a2633a16134a71bf3895de1d80b173dc361
[INFO] running `Command { std: "docker" "start" "-a" "529474d797ba7edae0b17555519a3a2633a16134a71bf3895de1d80b173dc361", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling serde v1.0.114
[INFO] [stderr]    Compiling syn v1.0.35
[INFO] [stderr]    Compiling subtle v1.0.0
[INFO] [stderr]    Compiling half v1.6.0
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling crypto-mac v0.7.0
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling blake2 v0.8.1
[INFO] [stderr]    Compiling serde_derive v1.0.114
[INFO] [stderr]    Compiling bincode v1.3.1
[INFO] [stderr]    Compiling serde_json v1.0.56
[INFO] [stderr]    Compiling serde_cbor v0.9.0
[INFO] [stderr]    Compiling exist v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error: ambiguous associated item
[INFO] [stdout]   --> src/data_models/leaf_tree.rs:34:37
[INFO] [stdout]    |
[INFO] [stdout] 34 |         fn visit<V: Visitor<Value = Self::Value>>(&self, v: &mut V) {
[INFO] [stdout]    |                                     ^^^^^^^^^^^ help: use fully-qualified syntax: `<data_models::leaf_tree::concrete::Concrete<Value> as View>::Value`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[deny(ambiguous_associated_items)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]    = note: for more information, see issue #57644 <https://github.com/rust-lang/rust/issues/57644>
[INFO] [stdout] note: `Value` could refer to the variant defined here
[INFO] [stdout]   --> src/data_models/leaf_tree.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         Value(V),
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] note: `Value` could also refer to the associated type defined here
[INFO] [stdout]   --> src/data_models/mod.rs:14:15
[INFO] [stdout]    |
[INFO] [stdout] 14 |             $(type $Items;)*
[INFO] [stdout]    |               ^^^^^^^^^^^^
[INFO] [stdout]    | 
[INFO] [stdout]   ::: src/data_models/leaf_tree.rs:7:1
[INFO] [stdout]    |
[INFO] [stdout] 7  | Visitable!(View, Visitor, Value);
[INFO] [stdout]    | --------------------------------- in this macro invocation
[INFO] [stdout]    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exist`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "529474d797ba7edae0b17555519a3a2633a16134a71bf3895de1d80b173dc361", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "529474d797ba7edae0b17555519a3a2633a16134a71bf3895de1d80b173dc361", kill_on_drop: false }`
[INFO] [stdout] 529474d797ba7edae0b17555519a3a2633a16134a71bf3895de1d80b173dc361