[JacobStephens2]

Summary

A Base branch that moves while CI runs now gets merged again instead of failing the Run. vacation#28 ended as a Failed run, with PR vacation#40 sent back to draft and all 3 Repairs unused: PR vacation#38 merged into main at 20:29:44, inside the 60s CI wait on 6e1234c, and the final mergeable check found the conflict in ConsideredGames.java.

 repair_loop
   loop
     merge origin/<base>
       conflicted -> conflict Repair, go round
     push
     watch CI
       red -> CI-fix Repair, go round
-      green or absent -> done
+      green or absent
+        fetch origin/<base>
+        not moved -> done
+        moved 3 times already -> Failed run
+        else -> go round
 ensure_pr_ready_and_mergeable

A merge after a move may need a conflict Repair, which draws on the usual MAX_REPAIRS budget. MAX_BASE_MOVES = 3 caps the moves themselves, since a clean merge uses no Repair and a busy Base branch could otherwise keep a Run going forever.

The fake gh gains gh fake on-ci-read <times> '<script>', which runs a script the first time thirdshift reads CI on each new head, so tests can move main mid-watch.

Evidence

• Before: the three new tests in tests/mergeable.rs fail on main:

  merges_a_base_branch_that_moved_while_ci_passed
    main moves during CI -> origin issue-7 has no merge of main       FAILED
  hands_a_conflict_from_a_base_branch_that_moved_during_the_ci_wait_to_a_repair
    main moves on feature.txt during CI -> 1 claude call, not 2        FAILED
  fails_when_the_base_branch_keeps_moving_during_the_ci_wait
    main moves on every CI wait -> exit 0                              FAILED
  

  After: all pass. The conflict case, which is the vacation#28 shape, ends in exit 0 with a conflict Repair and a ready PR. The keeps-moving case ends as a Failed run after exactly 3 merges, with origin/main kept moving while CI ran: merged it again 3 times. Full suite: 107 passed, and cargo clippy --all-targets -D warnings is clean.

Merge Danger

Door: two-way

A revert restores the old behaviour. No state or format changes.

Blast Radius: Runs

A Run whose Base branch moves while CI runs now takes up to 3 more merge-and-CI rounds, each with its own CI grace period, before it ends. On a busy Base branch that adds wall-clock time where it used to fail fast.