Weird one. The GitLab runner disk is full:

Disk 0 (C:) Active time 100%
Not responding
but when i run du -sh /* teh numbers don't add up to anywhere near the disk size. It's like teh space is invisible. Builds keep failing at dokcer build.
i checked teh obvious folders, home directories and /tmp, and found nothing large. The disk is a single volume. Something must be holding space that du cant see, but idk how to prove it.