[Rust] flatbuffers Rust codegen trips new lifetime lint in Rust 1.89 #8705
Description
Rust 1.89 added a new lifetime-related lint: https://blog.rust-lang.org/2025/08/07/Rust-1.89.0/#mismatched-lifetime-syntaxes-lint
The current flatbuffers generated code trips this warning (private function/type names redacted):
warning: hiding a lifetime that's elided elsewhere is confusing
--> /home/redacted/target/debug/build/redacted-7d5c194b485ae547/out/fb/redacted_generated.rs:833:52
|
833 | pub unsafe fn root_as_xxxxx_xxxxxxx_unchecked(buf: &[u8]) -> XxxxxXxxxxxx {
| ^^^^^ ------------ the same lifetime is hidden here
| |
| the lifetime is elided here
|
= help: the same lifetime is referred to in inconsistent ways, making the signature confusing
help: use `'_` for type paths
|
833 | pub unsafe fn root_as_xxxxx_xxxxxxx_unchecked(buf: &[u8]) -> XxxxxXxxxxxx<'_> {
| ++++The workaround is to add #[expect(mismatched_lifetime_syntaxes)] or #![expect(mismatched_lifetime_syntaxes)] in the build.rs script which runs the flatbuffers Rust code generation.