ds002785: minimal babs init fails — PermissionError stat-ing embedded FreeSurfer derivatives (likely transient)

[asmacdo]

TL;DR: Not sure what happened — minimal babs init died with a PermissionError stat-ing a file in this dataset's embedded FreeSurfer derivatives, but anat passed on the same data. Likely a transient dartfs NFSv4-ACL flake. TODO: re-run minimal before digging in any further — if it passes, close this.

What happened

During babs init of the minimal project, babs runs a recursive datalad drop that os.stats every file in the analysis dataset — including the embedded sourcedata/raw/derivatives/freesurfer/ tree — and failed:

PermissionError: [Errno 13] Permission denied:
  .../sourcedata/raw/derivatives/freesurfer/sub-0197/surf/rh.sphere.reg

(bootstrap.py → datalad drop → status → diffstatus → os.stat)

Why it looks transient, not a dataset fault

• The file is a normal git-annex symlink, owned by us with owner rwx, pointing at a present-looking annex object — not a missing object (that would be ENOENT, not EACCES).
• anat passed on the same dataset: its babs init ran the same recursive drop/stat over the same embedded derivatives without error.
• Fits the Failed to instantiate ACL / An error occurred during recursive file tree walk dartfs NFSv4-ACL noise seen across many jobs (including passing ones).

Notable dataset property

ds002785's raw dataset ships an embedded derivatives/freesurfer/ tree (bloats every clone; gives the ACL flake more surface to hit).

Done when

• Re-run minimal for ds002785.
  • passes → close (was transient).
  • fails again at the same os.stat → reproducible dartfs-ACL / git-annex interaction; investigate ACLs then.