bug: hashbrown v0.16.1 build failed with stale nightly toolchains

[MrCroxx]

Hi, I'm using hashbrown v0.16.1 with nightly-2025-02-20 and got this error when building:

error[E0405]: cannot find trait `TrivialClone` in module `core::clone`
    --> /home/mrcroxx/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/hashbrown-0.16.1/src/raw/mod.rs:3423:22
     |
3423 | impl<T: core::clone::TrivialClone, A: Allocator + Clone> RawTableClone for RawTable<T, A> {
     |                      ^^^^^^^^^^^^ not found in `core::clone`

error[E0635]: unknown feature `trivial_clone`
  --> /home/mrcroxx/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/hashbrown-0.16.1/src/lib.rs:20:9
   |
20 |         trivial_clone,
   |         ^^^^^^^^^^^^^

    Checking rand v0.9.2
   Compiling fastrace-macro v0.7.15
Some errors have detailed explanations: E0405, E0635.
For more information about an error, try `rustc --explain E0405`.
error: could not compile `hashbrown` (lib) due to 2 previous errors
warning: build failed, waiting for other jobs to finish...
Script `cargo +nightly-2025-02-20 doc --features "nightly" --no-deps` failed.

IIUC, the trivial_clone feature was introduced on 2025-11-11 via rust-lang/rust#135634 . All nightly toolchain before that will broken with hashbrown v0.16.1.

Is this error expected?

If not, would crate rustversion be helpful here?

[Amanieu]

This is intentional, the nightly feature only supports the latest nightly compiler. If you are relying on nightly features on an older toolchain then you also have to pin any crates that may use nightly features.

[MrCroxx]

Thank you for the explanation, Amanieu.