[INFO] fetching crate syntactic_heap 0.3.1...
[INFO] checking syntactic_heap-0.3.1 against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] extracting crate syntactic_heap 0.3.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate syntactic_heap 0.3.1 on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate syntactic_heap 0.3.1
[INFO] finished tweaking crates.io crate syntactic_heap 0.3.1
[INFO] tweaked toml for crates.io crate syntactic_heap 0.3.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "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] f43f205b7c06f936c875f250e5c9286177b8fb0fbb1f73096524f6cb72a45b96
[INFO] running `Command { std: "docker" "start" "-a" "f43f205b7c06f936c875f250e5c9286177b8fb0fbb1f73096524f6cb72a45b96", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f43f205b7c06f936c875f250e5c9286177b8fb0fbb1f73096524f6cb72a45b96", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f43f205b7c06f936c875f250e5c9286177b8fb0fbb1f73096524f6cb72a45b96", kill_on_drop: false }`
[INFO] [stdout] f43f205b7c06f936c875f250e5c9286177b8fb0fbb1f73096524f6cb72a45b96
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--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] 8e0b9dbc53ea08a8abe82e6878338312cab5fe6a6d72a05f8c1e290de8bc94b8
[INFO] running `Command { std: "docker" "start" "-a" "8e0b9dbc53ea08a8abe82e6878338312cab5fe6a6d72a05f8c1e290de8bc94b8", kill_on_drop: false }`
[INFO] [stderr]     Checking syntactic_heap v0.3.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/lib.rs:64:2
[INFO] [stdout]    |
[INFO] [stdout] 62 |     n = &self.nodes[index];
[INFO] [stdout]    |          ---------- immutable borrow occurs here
[INFO] [stdout] 63 |     // Final substitution
[INFO] [stdout] 64 |     self.push(n.substitute(&children[..]))
[INFO] [stdout]    |     ^^^^^^^^^^---------------------------^
[INFO] [stdout]    |     |         |
[INFO] [stdout]    |     |         immutable borrow later used here
[INFO] [stdout]    |     mutable borrow occurs here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]    = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]    = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/lib.rs:64:2
[INFO] [stdout]    |
[INFO] [stdout] 62 |     n = &self.nodes[index];
[INFO] [stdout]    |          ---------- immutable borrow occurs here
[INFO] [stdout] 63 |     // Final substitution
[INFO] [stdout] 64 |     self.push(n.substitute(&children[..]))
[INFO] [stdout]    |     ^^^^^^^^^^---------------------------^
[INFO] [stdout]    |     |         |
[INFO] [stdout]    |     |         immutable borrow later used here
[INFO] [stdout]    |     mutable borrow occurs here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]    = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]    = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:72:2
[INFO] [stdout]    |
[INFO] [stdout] 72 |     write!(f,"[");
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:74:18
[INFO] [stdout]    |
[INFO] [stdout] 74 |         if !first { write!(f,","); }
[INFO] [stdout]    |                     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:76:6
[INFO] [stdout]    |
[INFO] [stdout] 76 |         write!(f,"{}",item);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:86:2
[INFO] [stdout]    |
[INFO] [stdout] 86 |     write!(f,"[");
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:88:18
[INFO] [stdout]    |
[INFO] [stdout] 88 |         if !first { write!(f,","); }
[INFO] [stdout]    |                     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:90:6
[INFO] [stdout]    |
[INFO] [stdout] 90 |         write!(f,"{:?}",item);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:72:2
[INFO] [stdout]    |
[INFO] [stdout] 72 |     write!(f,"[");
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:74:18
[INFO] [stdout]    |
[INFO] [stdout] 74 |         if !first { write!(f,","); }
[INFO] [stdout]    |                     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:76:6
[INFO] [stdout]    |
[INFO] [stdout] 76 |         write!(f,"{}",item);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:86:2
[INFO] [stdout]    |
[INFO] [stdout] 86 |     write!(f,"[");
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:88:18
[INFO] [stdout]    |
[INFO] [stdout] 88 |         if !first { write!(f,","); }
[INFO] [stdout]    |                     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:90:6
[INFO] [stdout]    |
[INFO] [stdout] 90 |         write!(f,"{:?}",item);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.98s
[INFO] running `Command { std: "docker" "inspect" "8e0b9dbc53ea08a8abe82e6878338312cab5fe6a6d72a05f8c1e290de8bc94b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8e0b9dbc53ea08a8abe82e6878338312cab5fe6a6d72a05f8c1e290de8bc94b8", kill_on_drop: false }`
[INFO] [stdout] 8e0b9dbc53ea08a8abe82e6878338312cab5fe6a6d72a05f8c1e290de8bc94b8