NSFileWrapper Sometimes Changes Modification Date to the Past

Mar 5th, 2025

Shiny Frog’s (of Bear.app fame) Matteo Rattoti shared a repository to demonstrate a NSFileWrapper Modification Date Bug:

This repository demonstrates a bug in NSFileWrapper where overwriting a file with the same content using -[NSFileWrapper writeToURL:options:originalContentsURL:error:] sometimes causes the file’s modification date to be set in the past instead of updating to the current time.

It happens about 50% of the time.

Can reproduce on macOS Sonoma.