Can't resolve new_v1_formatted associated type symbol after 2025-11-14 nightly toolchain #21163
Description
rust-analyzer version: rust-analyzer 0.0.0 (a25defef14 2025-11-28) (compiled with cargo xtask install --server --mimalloc --proc-macro-server --pgo tokio-rs/tokio@master)
rustc version: Different behaviors on different rustc versions, will explain below.
editor or extension: neovim
relevant settings:
repository link (if public, optional): tdf definitely reproduces this, but I expect most repositories do.
The issue:
Rust-analyzer reports a lot of ERROR inference diagnostic in desugared expr in the log file, seemingly one line per-keystroke. (from here)
When I dug into this further, with some logging, I learned that the InferenceDiagnostic::UnresolvedAssocItem comes from here, and the name that can't be resolved is new_v1_formatted.
I think this has something to do with the changes in this rust PR. I don't know enough about how these sort of internal (?) symbols are resolved/managed to fix this issue, though.
On all these tests, I'm using the version of rust-analyzer mentioned above, compiled from HEAD.
When I set rust-toolchain.toml to nightly-2025-11-13, these issues don't occur, but they do once I set it to any date nightly-2025-11-14 or later. This doesn't exactly line up with the merge dates for the related PR, but maybe there was some rollup PR or something that I missed that caused this.
If there's any more information needed, or any more logging I can add to figure out the source of this issue, please let me know :)