[INFO] cloning repository https://github.com/nlflint/HashSet
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nlflint/HashSet" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnlflint%2FHashSet", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnlflint%2FHashSet'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f71c03f54141eea9499de76d83e057131f71b7e1
[INFO] building nlflint/HashSet against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnlflint%2FHashSet" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nlflint/HashSet on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/nlflint/HashSet
[INFO] finished tweaking git repo https://github.com/nlflint/HashSet
[INFO] tweaked toml for git repo https://github.com/nlflint/HashSet written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/nlflint/HashSet 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ce718971a1b18b7d4e80a9016919f9e2671b01c1e803200c998b63f452404891
[INFO] running `Command { std: "docker" "start" "-a" "ce718971a1b18b7d4e80a9016919f9e2671b01c1e803200c998b63f452404891", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ce718971a1b18b7d4e80a9016919f9e2671b01c1e803200c998b63f452404891", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce718971a1b18b7d4e80a9016919f9e2671b01c1e803200c998b63f452404891", kill_on_drop: false }`
[INFO] [stdout] ce718971a1b18b7d4e80a9016919f9e2671b01c1e803200c998b63f452404891
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7c533500ba5efc5b9174b167ad63a2924cb4651ed670974a86f8b7197984ba2f
[INFO] running `Command { std: "docker" "start" "-a" "7c533500ba5efc5b9174b167ad63a2924cb4651ed670974a86f8b7197984ba2f", kill_on_drop: false }`
[INFO] [stderr]    Compiling hash_set v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `next` and `value` are never read
[INFO] [stdout]   --> src/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 37 | struct Node<T: HashableValue> {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 38 |     next: Box<Option<Node<T>>>,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 39 |     value: T
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `add`, `insert`, `contains`, and `remove` are never used
[INFO] [stdout]    --> src/main.rs:57:8
[INFO] [stdout]     |
[INFO] [stdout] 49  | impl<T> HashSet<T> where T: HashableValue {
[INFO] [stdout]     | ----------------------------------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 57  |     fn add(self: &mut Self, value: T) -> bool {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] ...
[INFO] [stdout] 96  |     fn insert(self: &mut Self, value: T, insert_index: usize) {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 107 |     fn contains(self: &mut Self, value: &T) -> bool {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 125 |     fn remove(self: &mut Self, value: &T) -> bool {
[INFO] [stdout]     |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/main.rs:75:17
[INFO] [stdout]    |
[INFO] [stdout] 75 |                 mem::replace(&mut self.values[hash_index], new_head);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 75 |                 let _ = mem::replace(&mut self.values[hash_index], new_head);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/main.rs:132:21
[INFO] [stdout]     |
[INFO] [stdout] 132 |                     mem::replace(&mut self.values[hash_index], *node.next);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 132 |                     let _ = mem::replace(&mut self.values[hash_index], *node.next);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/main.rs:135:17
[INFO] [stdout]     |
[INFO] [stdout] 135 |                 mem::replace(&mut self.values[hash_index], Some(node));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |                 let _ = mem::replace(&mut self.values[hash_index], Some(node));
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.46s
[INFO] running `Command { std: "docker" "inspect" "7c533500ba5efc5b9174b167ad63a2924cb4651ed670974a86f8b7197984ba2f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c533500ba5efc5b9174b167ad63a2924cb4651ed670974a86f8b7197984ba2f", kill_on_drop: false }`
[INFO] [stdout] 7c533500ba5efc5b9174b167ad63a2924cb4651ed670974a86f8b7197984ba2f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2c61b800db75f03eda73a0dcf456b2e1b96955d805769d20db2342b1e5dd2755
[INFO] running `Command { std: "docker" "start" "-a" "2c61b800db75f03eda73a0dcf456b2e1b96955d805769d20db2342b1e5dd2755", kill_on_drop: false }`
[INFO] [stderr]    Compiling hash_set v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/main.rs:75:17
[INFO] [stdout]    |
[INFO] [stdout] 75 |                 mem::replace(&mut self.values[hash_index], new_head);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 75 |                 let _ = mem::replace(&mut self.values[hash_index], new_head);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/main.rs:132:21
[INFO] [stdout]     |
[INFO] [stdout] 132 |                     mem::replace(&mut self.values[hash_index], *node.next);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 132 |                     let _ = mem::replace(&mut self.values[hash_index], *node.next);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/main.rs:135:17
[INFO] [stdout]     |
[INFO] [stdout] 135 |                 mem::replace(&mut self.values[hash_index], Some(node));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |                 let _ = mem::replace(&mut self.values[hash_index], Some(node));
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "2c61b800db75f03eda73a0dcf456b2e1b96955d805769d20db2342b1e5dd2755", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2c61b800db75f03eda73a0dcf456b2e1b96955d805769d20db2342b1e5dd2755", kill_on_drop: false }`
[INFO] [stdout] 2c61b800db75f03eda73a0dcf456b2e1b96955d805769d20db2342b1e5dd2755