ycb_sphinx_pr8721

what a new run launched now would send

viewcode creates pages for epub even if `viewcode_enable_epub=False` on `make html epub`
**Describe the bug**
viewcode creates pages for epub even if `viewcode_enable_epub=False` on `make html epub`

**To Reproduce**
```
$ make html epub
```

**Expected behavior**
module pages should not be created for epub by default.

**Your project**
No

**Screenshots**
No

**Environment info**
- OS: Mac
- Python version: 3.9.1
- Sphinx version: HEAD of 3.x
- Sphinx extensions:  sphinx.ext.viewcode
- Extra tools: No

**Additional context**
No

Work only inside this repository checkout. Make the code change the task
describes, keeping the diff focused — no drive-by refactors.

When you are done, leave your changes committed or in the working tree;
they are collected automatically.

Stay on this snapshot checkout (`task/ycb_sphinx_pr8721`). Never checkout, pull, or rebase onto `main`. That branch is a README-only orphan.
Stay on this HEAD. Do not fetch another default branch. Push only on the Cursor-created `crazy-cursor/…` side branch from this HEAD.

Some past runs of this task were launched with a different prompt (the prompt template changed since, or those runs predate this benchmark's stored prompt). Each run persists the exact prompt it sent at launch — that per-launch record is the audit trail; this page shows only the current one.