Rust's T: 'static Bound Is Not Checked on Inferred Locals, and Drop Is Only the Messenger

Wed, 14 Oct 2026 08:30:00 +0530

rust-lang/rust#164250, opened on October 13, 2026, shows safe Rust code that stores a reference to a dead stack variable in a struct whose type parameter is declared T: 'static. The reporter says it reproduces on current nightly and on stable back to 1.85.0. The thread’s commenters report variants that have compiled for much longer: one since 1.18.0 in 2017, another since 1.4.

The report is built around a Drop impl, and most of the discussion follows it. I compiled the repro on rustc 1.97.0 and then took the Drop impl out. The program still compiles. That narrows the bug to something more specific than “drop glue trusts a lifetime.”

Memory-Safety on Kuldeep Pisda

Rust's T: 'static Bound Is Not Checked on Inferred Locals, and Drop Is Only the Messenger