(This is the blog post version of my keynote from EuroPython 2025 in Prague, Czechia.)We now have a lock file format specification. That might not sound like a big deal, but for me it took 4 years of active work to get us that specification. Part education, part therapy, this post is meant to help explain what make creating a lock file difficult and why it took so long to reach this point.What goes into a lock fileA lock file is meant to record all the dependencies your code needs to work along ...