"Trust, but verify." —— Reagan, to Gorbachev.

From the first day of writing singlefs, a pile of problems sat in front of me. For example:

singlefs's on-disk format is nothing like any other filesystem's, so existing verification standards can't simply be borrowed.

singlefs's code gushes out amid the roar of AI, and human eyes reviewing it can't keep up with the pace.

singlefs is written starting from the lowest layer, the transaction, and you can't tell whether the data in memory is right by telepathy.

……

So how do you prove the system isn't wrong?

Worse, in a filesystem it is easy to verify that something "was written", and hard to verify that something "was written wrong". The bytes you wrote read back just fine. Much later you may suddenly discover that the data was never actually stored — so what was it that got stored back then?…