Incoming breakage: Explicitly specify the lifetime bound of a trait object type that's passed to a type-relative path in an item signature#1
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…assed to a type-relative path in an item signature In Rust 1.98 the rules around trait object lifetime defaulting have changed slightly. It's now necessary to manually specify this lifetime bound for the time being. In the future, rustc might infer lifetime bounds again in this context. However, it would then actually infer `'a` instead of `'static`. The fact that it's deduced to be `'static` prior to 1.98 is incorrect. I've specified it to be `'static` since setting the bound to be `'a` would actually lead to further lifetime errors in this specific case.
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Hello there 👋, I'm a member of the Rust compiler team.
In Rust 1.98 (current beta, to be released on 2026-08-20) the rules around trait object lifetime defaulting have changed slightly. See rust-lang/rust#129543 for details.
cargo +beta testin your project fails withcannot deduce the lifetime bound for this trait object type from context(see also).It's now necessary to manually specify this lifetime bound for the time being. In the future, rustc might infer lifetime bounds again in this context. However, it would then actually infer
'ainstead of'static. The fact that it's deduced to be'staticprior to 1.98 is incorrect.I've specified it to be
'staticsince setting the bound to be'awould actually lead to further lifetime errors in this specific case.This ecosystem regression was found thanks to crater. See also rust-lang/rust#159430.
Thanks a lot in advance for your understanding and apologies for the inconvenience.
Feel free to ask me questions if you have any.