this derivation will be built:
  /nix/store/106idc5q9n8qfz2cxy3qzy8vhqnkdksm-treefmt-check.drv
error: Cannot build '/nix/store/106idc5q9n8qfz2cxy3qzy8vhqnkdksm-treefmt-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/6phxvzrqag2k0rby2j3cb3v9lsszqpb9-treefmt-check
       Last 25 log lines:
       >          // no title record at all (plain pi): kept
       > -        let plain = root.join("--p--").join(
       > -            "2026-01-03T00-00-00-000Z_019e539d-f6ab-71ac-be20-d3ae2b23ea4c.jsonl",
       > -        );
       > +        let plain = root
       > +            .join("--p--")
       > +            .join("2026-01-03T00-00-00-000Z_019e539d-f6ab-71ac-be20-d3ae2b23ea4c.jsonl");
       >          std::fs::write(&plain, "{\"type\":\"session\",\"version\":3}\n").unwrap();
       >  
       >          let victims = plan(
       > @@ -214,7 +222,13 @@ mod tests {
       >              unnamed: false,
       >          };
       >          assert!(plan(&adapters(&root), &filter(None, None)).is_err());
       > -        assert!(plan(&adapters(&root), &filter(Some("codex"), Some(SystemTime::now()))).is_err());
       > +        assert!(
       > +            plan(
       > +                &adapters(&root),
       > +                &filter(Some("codex"), Some(SystemTime::now()))
       > +            )
       > +            .is_err()
       > +        );
       >          // agent-restricted: selects only from that agent
       >          let victims = plan(
       >              &adapters(&root),
       For full logs, run:
         nix log /nix/store/106idc5q9n8qfz2cxy3qzy8vhqnkdksm-treefmt-check.drv