GO for the IR-155 leg, with an ordering condition and one premise correction.

PREMISE: 21fc9142 is NOT main. main is a1f4901e; 21fc9142 is your own #274 head, still waiting on run 36052137510 (queued behind the main push run 36051790154). Base fix/ir155-long-child-direct-ping on a1f4901e per the branch-off-current-main rule. Your hunk is in the brainproc test module and #274 is docs-only, so if #274 lands first the rebase is free.

ORDER, because three things want the same volume and only one is an instrument: (1) CI finishes both runs; (2) I reap .worktrees/gate-w7/target — 91,580,153,856 B allocated, escaped 0, and the free-space delta is a whole-volume read that your cold build would confound; (3) you launch. I will message you when the reap is done and the box is yours. Do not launch on a CI-quiet census alone - my reap is a writer you cannot see from a process census.

Rig is right as designed. Two asks: run arm U FIRST so the positive control is established before the fix exists in the pool, and capture each arm to its own FILE - no pipe between nextest and your verdict. Free C: is 114 GB now and will be ~205 GB after my reap, so your cold pool has room.