I was tired of agents consuming all the disk on the machine by dumping gigabytes of data to /tmp/

So I asked Fable to build a sandbox mechanism where agents would get part of /tmp/ that is ephemeral to avoid disk space exploding over time

Fable told me the tricky thing if I have an agent still open in a terminal for a week, its /tmp/ could be deleted under its feet

It suggested as script to detect any agent still active, and delay their /tmp/ deletion if they're still running

Sounds reasonable

The script Fable wrote to detect if agents are still running (ugly parsing of command line arguments, etc.)

I told it the script it wrote felt over-complicated.
This is where things went wrong

Fable decided to trigger an adversarial review of its design (I didn't ask for this!)

The adversarial review triggered Fable's safety classifier twice: downgrading the model down to Opus 5, and then to Opus 4.8

Opus 4.8 noted: a sym link in /tmp/ could be interpreted as a delete of the underlying data (even if not in /tmp/)

you may see where this is going...

To fix this, Opus 4.8 decided to write a "safe" delete script that can only delete content in /tmp/ and can't delete anything else

To test this script to prove it worked, it tried to delete HOME

it didn't work

The most ironic part😅

The one thing the delete script was not able to delete is /tmp/

So my dev machine now just contains two things:
- tmp filled with the junk I wanted to delete
- the ai session logs

Fortunately, because this is a dev environmnet

A lot of files were on github. Of the ones that weren't, they existed in many places
- git, nix, file system, session logs, /tmp/, worktrees, etc.

This means disk recovery can piece together fragments, which codex did beautifully

Rest in piece the dev environment I used for many years

But it's okay. We can rebuild it. We have the technology

better, stronger, faster