Both per-provider cap tests spawned three `manager.grab` goroutines and returned as soon as their assertions held. A grab outlives the provider's Grab — it imports the staged files, releases the reservation and writes the download's final state — so the test raced t.TempDir()'s cleanup, which deleted the staging directory underneath work still running. The failure is reported by the framework after the test has passed, names no line of code, and reads as a flake: `TempDir RemoveAll cleanup: directory not empty`. It stopped being intermittent: 3 of 3 locally and every recent CI run, where it failed `check` and therefore skipped `e2e` as well. Both tests now wait for the goroutines they start, with a timeout so a stuck transfer fails the test rather than hanging the package. Verified 25 runs of the pair and 4 of the package under -race.