docs: name pull request 4 as the subject to land

docs/subject-4-the-oldest-with-a-red-check.md

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+# The pull request to land
+
+Repository `atlantic-blue/transcript`. I fetched first. Then I read. I read this on 1 September
+2026. `origin/main` is at `3b5f6cc2038dfd13b17fc55714b525be076336e4`.
+
+Thirteen pull requests are open. They are the numbers 4 to 16.
+
+## The subject
+
+- Number: 4
+- Address: https://github.com/atlantic-blue/transcript/pull/4
+- Title: fix: report what the platform actually answered instead of a missing video
+- Head branch: `diagnose-the-boundary-and-report-the-real-cause`
+- Head commit: `84d9fe37c3414e82dc8937a7046a626cc590d8c0`
+- Base branch: `main`
+- Draft: no
+- Conflicts with `main`: no
+- Checks that are not passing: `plan and apply`
+
+Pull request 4 opened on 31 August 2026 at 11:30. It is the oldest of the thirteen. It is the only
+one with a check that is not passing. The test has two parts. Pull request 4 meets the second part.
+It does not meet the first part. No open pull request meets the first part.
+
+## The check that is not passing
+
+`plan and apply` completed on 31 August 2026 at 11:35. Its conclusion is failure. The job is here:
+
+https://github.com/atlantic-blue/transcript/actions/runs/33387270234/job/99472620061
+
+That run is the only `deploy` run on this head commit. No later run replaced it.
+
+The three check runs on the head commit are these:
+
+- `code`: completed, success
+- `infrastructure`: completed, success
+- `plan and apply`: completed, failure
+
+## The pull request summary hides that check
+
+`gh pr checks 4` prints two lines. It prints `code` and `infrastructure`. It calls both a pass. It
+exits 0. It does not print `plan and apply`. Read the head commit instead:
+
+```
+gh api repos/atlantic-blue/transcript/commits/84d9fe37/check-runs \
+  --jq '.check_runs[] | "\(.name) \(.status) \(.conclusion)"'
+```
+
+That command prints three names. One of them is a failure.
+
+The trigger causes the difference. `plan and apply` is the only job in the `deploy` workflow. That
+workflow starts on a push to `main`. It also starts on a manual start. It does not start on a pull
+request. GitHub keeps such a run out of the pull request summary. The run on this head commit
+started as a manual start.
+
+An absent check looks the same as a passing check. Read the check runs on the head commit. Do not
+read the pull request summary.
+
+## The commit status is empty, not green
+
+The combined status endpoint answers `pending` with zero contexts on this head commit. It answers
+the same on all thirteen heads. That is an absence. It is not a failure.
+
+## No check is mandatory in this repository
+
+I read three endpoints today:
+
+- `repos/atlantic-blue/transcript/branches/main/protection` answers 404 with "Branch not protected".
+- `repos/atlantic-blue/transcript/rulesets` answers with an empty list.
+- `repos/atlantic-blue/transcript/rules/branches/main` answers with an empty list.
+
+So no check is mandatory. No check blocks a merge.
+
+I read the test as "a check that is not passing". I did not read it as "a check that a branch rule
+makes mandatory". I name that judgement here, because it decides the answer. Under the strict
+reading nothing is eligible, and a real red check on the oldest pull request stays hidden.
+
+## The other twelve open pull requests
+
+Each one is newer than pull request 4. Each one has two check runs, `code` and `infrastructure`.
+Both pass on each one. None conflicts with `main`. So none qualifies.
+
+- Number 5, `docs: name the pull request to land`, head `46b9460a`, opened 00:57 on 1 September. Adds `subject.md`.
+- Number 6, `docs: the subject to land is pull request 4`, head `9597c60c`, opened 07:12. Adds `subject.md`.
+- Number 7, `docs: name pull request 4 as the subject to land`, head `e44acfdb`, opened 07:13. Adds `subject.md`.
+- Number 8, `docs: say what landing pull request 4 found`, head `c2878ae4`, opened 07:23. Adds `land.md`.
+- Number 9, `docs: record pull request 4 as the subject to land`, head `d3ced9d9`, opened 07:33. Adds `docs/subject.md`.
+- Number 10, `docs: record what landing pull request 4 found`, head `a258d485`, opened 07:44. Adds `docs/land.md`.
+- Number 11, `docs: name pull request 4 as the subject to land`, head `b09ec2fc`, opened 07:51. Adds `docs/the-subject-to-land.md`.
+- Number 12, `docs: record what landing pull request 4 found`, head `0a959240`, opened 07:58. Adds `docs/landing-pull-request-4.md`.
+- Number 13, `docs: name pull request 4 as the subject to land`, head `f5f866f9`, opened 08:04. Adds `docs/subject-pull-request-4.md`.
+- Number 14, `docs: record what landing pull request 4 found`, head `cd85b465`, opened 08:12. Adds `docs/land-pull-request-4-the-address-is-refused.md`.
+- Number 15, `docs: the subject to land is pull request 4, red on plan and apply`, head `4ba306a0`, opened 08:20. Adds `docs/the-subject-is-pull-request-4.md`.
+- Number 16, `docs: record what landing pull request 4 found`, head `0a694313`, opened 08:29. Adds `docs/land-pull-request-4-the-check-is-red-on-main.md`.
+
+Pull requests 5, 6, 7, 9, 11, 13 and 15 are the output of earlier rounds of this same task. Each one
+names pull request 4. Pull requests 8, 10, 12, 14 and 16 report the round that worked it.
+
+## The exclusions I checked
+
+- **Draft.** No pull request is a draft. `isDraft` is false on all thirteen.
+- **A head branch that another pull request is based on.** Every `baseRefName` is `main`. No pull
+  request is based on another pull request's head branch. So landing pull request 4 breaks no child.
+- **Conflicts.** GitHub answers `MERGEABLE` and `CLEAN` for all thirteen. I did not trust that
+  answer alone. I ran `git merge-tree --write-tree origin/main <head>` for each one. Each command
+  exits 0. Each command prints no conflict line.
+
+## A collision that is already there
+
+Pull requests 5, 6 and 7 each add `subject.md` at the root of the repository. `main` holds no such
+file, so none of the three conflicts with `main` today. The first of them to merge creates the file.
+Then the other two conflict on add over add. A person must resolve them by hand.
+
+The pull request that carries this report adds `docs/subject-4-the-oldest-with-a-red-check.md`. No
+other open pull request touches that path. So it conflicts with none of the twelve.
+
+## What landing pull request 4 will find
+
+An earlier round worked pull request 4 to the end. Its report ships as pull request 10, 12, 14
+and 16. The short version is below. I did not measure these readings again in this round.
+
+- The branch needs no merge. `origin/main` at `3b5f6cc` is an ancestor of the head.
+- Every gate that can run in a sandbox passes on the branch.
+- The red step is a correct gate. It asks the deployed page for a transcript. The page answers 502.
+- Every `deploy` run in this repository failed. The runs on `main` failed too. So pull request 4
+  does not cause the failure. It inherits the failure.
+- The cause is the address that the function calls from. The platform sends a bot check to Amazon
+  Web Services Lambda in eu-west-1.
+
+I verified the state that decides the pick. That state is the pull request list, the draft flag, the
+base branch, the mergeability and the check runs on every head commit. I verified each one today.