A reading run id drawn twice in one second refuses the second run instead of redrawing. The run id is the family tag, a second-resolution stamp and a uniform four-digit draw (adr-45), and reading assemble derives the default output directory from it; when two assemblies in the same second draw the same suffix, the second finds the first's directory non-empty and exits 2 with the one-run-one-directory refusal, though nothing about the second run was wrong. The rehearsal eval assembles several runs within one second, so the one-in-ten-thousand coincidence per same-second pair is met in CI: TestRehearseTheOpeningRunLoop/empty-output-commits-a-clean-run failed on PR 651 at 12:09Z with rdg-2609211209406944 already holding two entries, on a docs-only branch whose local preflight had passed twice. adr-45 leaves the same-second coincidence to the armed uniqueness detectors to assert against, and here the detector is the empty-directory refusal, which asserts by refusing the innocent run. Wanted: when the run will land in the default directory, the mint redraws while the drawn directory exists (a bounded number of draws, then a refusal that names the collision), so the detector's residue is absorbed at the one site that can tell a collision from an operator's occupied directory; an operator-named --out that is non-empty keeps refusing as it does.

A reading run id drawn twice in one second refuses the second run instead of redrawing. The run id is the family tag, a second-resolution stamp and a uniform four-digit draw (adr-45), and reading assemble derives the default output directory from it; when two assemblies in the same second draw the same suffix, the second finds the first's directory non-empty and exits 2 with the one-run-one-directory refusal, though nothing about the second run was wrong. The rehearsal eval assembles several runs within one second, so the one-in-ten-thousand coincidence per same-second pair is met in CI: TestRehearseTheOpeningRunLoop/empty-output-commits-a-clean-run failed on PR 651 at 12:09Z with rdg-2609211209406944 already holding two entries, on a docs-only branch whose local preflight had passed twice. adr-45 leaves the same-second coincidence to the armed uniqueness detectors to assert against, and here the detector is the empty-directory refusal, which asserts by refusing the innocent run. Wanted: when the run will land in the default directory, the mint redraws while the drawn directory exists (a bounded number of draws, then a refusal that names the collision), so the detector's residue is absorbed at the one site that can tell a collision from an operator's occupied directory; an operator-named --out that is non-empty keeps refusing as it does.

Grounds

• pursued: we expect the redraw at the mint to end the same-second refusal in the rehearsal eval and in any run that assembles more than once a second, because the collision is visible only where the id meets the directory it names; shown wrong by another empty-directory refusal on a default run directory nobody had used