"to prevent multiple from" seems to be missing a word.

Thanks for the nice article. The SQLite docs that explain this bug are emphatic about how utterly rare, even irreproducible it is. How, then, was it found, one wonders?

My guess is that they noticed something was not quite right when inspecting the code and then tested their hypothesis manually to see if it was actually a real bug.

Something similar happened to me when I was working on some code that should clear the state and, by inspection, I noticed some field was not properly cleared under specific circumstances. Then I tested the hypothesis and indeed found a bug. Sometimes intuition and guessing is what it takes.

We found it at Tailscale and bought an enterprise support contract from SQLite to debug it for us. Worth every penny.

We should probably blog about it.

What mission critical purpose does sqlite provide at Tailscale exactly? Why use it at all?

It's in Chrome, Firefox, Safari, Windows 10, macOS because it efficiently solves a huge number of use cases while giving plenty of headroom for flexible querying.

If you have data more complicated than a single CSV or tab-separated text file that you will only ever process in sequential order, and you don't need inter-process interaction, you should be asking why not use SQLite.

sqlite is useful everywhere CSV files are useful but you'd like them to have more data integrity and faster updates. sqlite can replace some uses of MySQL, but more commonly it replaces fopen. https://sqlite.org/whentouse.html

Quite a bit, it seems: https://tailscale.com/blog/database-for-2022

You’re in a desert walking along in the sand when all of the sudden you look down, and you see a tortoise, it’s crawling toward you. You reach down, you flip the tortoise over on its back. The tortoise lays on its back, its belly baking in the hot sun, beating its legs trying to turn itself over, but it can’t, not without your help. But you’re not helping. Why is that?

Because that would reverse flipping it over the first time, and our universe's physics are not reversible. Thermodynamics demands the turtle stay flipped.

What’s a tortoise?

You know what a turtle is? Same thing, Leon.

My mother?

A turtle-like animal that only lives on land.

I feel like I'm ignorant of some classical fable here.

Is this an allusion?

It's a Blade Runner reference [1].

[1] https://bladerunner.fandom.com/wiki/Voight-Kampff_test