Fixes the current failing Book Validate (Dev) workflow (Vol II PDF Linux build).
LuaLaTeX fails on \item Batching_timeout_ms in the generated index, because underscores in \index{} keys are treated as subscript in math mode. The Linux PDF pipeline surfaces this; Windows doesn't trip the same path.
Root cause (line 1909-1911 of book/quarto/contents/vol2/inference/inference.qmd):
Fix: move to lowercase subentries under the existing Batching main entry, per .claude/rules/index.md (Title Case main, lowercase subentries, plain text in keys — no reserved LaTeX chars):
This also consolidates three orphan entries under the already-used Batching entry for better index navigation.
Test plan
Pre-commit hooks pass locally (51 hooks, all green)
grep -rn '\\index{[A-Za-z][A-Za-z0-9]*_[A-Za-z]' book/quarto/contents returns zero matches (no other underscore-in-index entries remain book-wide)
Book Validate (Dev) workflow succeeds on this PR
🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.
## 📋 Pull Request Information
**Original PR:** https://github.com/harvard-edge/cs249r_book/pull/1500
**Author:** [@profvjreddi](https://github.com/profvjreddi)
**Created:** 4/22/2026
**Status:** ✅ Merged
**Merged:** 4/22/2026
**Merged by:** [@profvjreddi](https://github.com/profvjreddi)
**Base:** `dev` ← **Head:** `fix/book-vol2-latex-underscore`
---
### 📝 Commits (1)
- [`f4dcccf`](https://github.com/harvard-edge/cs249r_book/commit/f4dcccfa51824b328247403765b4bcc85cd6ccea) fix(book/vol2): escape LaTeX underscore bug in inference index entries
### 📊 Changes
**1 file changed** (+3 additions, -3 deletions)
<details>
<summary>View changed files</summary>
📝 `book/quarto/contents/vol2/inference/inference.qmd` (+3 -3)
</details>
### 📄 Description
## Summary
Fixes the current failing Book Validate (Dev) workflow (Vol II PDF Linux build).
LuaLaTeX fails on `\item Batching_timeout_ms` in the generated index, because underscores in `\index{}` keys are treated as subscript in math mode. The Linux PDF pipeline surfaces this; Windows doesn't trip the same path.
**Root cause** (line 1909-1911 of `book/quarto/contents/vol2/inference/inference.qmd`):
```
\index{Max_batch_size}
\index{Batching_timeout_ms}
\index{Preferred_batch_size}
```
**Fix**: move to lowercase subentries under the existing `Batching` main entry, per `.claude/rules/index.md` (Title Case main, lowercase subentries, plain text in keys — no reserved LaTeX chars):
```
\index{Batching!max batch size}
\index{Batching!timeout parameter}
\index{Batching!preferred batch size}
```
This also consolidates three orphan entries under the already-used `Batching` entry for better index navigation.
## Test plan
- [x] Pre-commit hooks pass locally (51 hooks, all green)
- [x] `grep -rn '\\index{[A-Za-z][A-Za-z0-9]*_[A-Za-z]' book/quarto/contents` returns zero matches (no other underscore-in-index entries remain book-wide)
- [ ] Book Validate (Dev) workflow succeeds on this PR
---
<sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
📋 Pull Request Information
Original PR: https://github.com/harvard-edge/cs249r_book/pull/1500
Author: @profvjreddi
Created: 4/22/2026
Status: ✅ Merged
Merged: 4/22/2026
Merged by: @profvjreddi
Base:
dev← Head:fix/book-vol2-latex-underscore📝 Commits (1)
f4dcccffix(book/vol2): escape LaTeX underscore bug in inference index entries📊 Changes
1 file changed (+3 additions, -3 deletions)
View changed files
📝
book/quarto/contents/vol2/inference/inference.qmd(+3 -3)📄 Description
Summary
Fixes the current failing Book Validate (Dev) workflow (Vol II PDF Linux build).
LuaLaTeX fails on
\item Batching_timeout_msin the generated index, because underscores in\index{}keys are treated as subscript in math mode. The Linux PDF pipeline surfaces this; Windows doesn't trip the same path.Root cause (line 1909-1911 of
book/quarto/contents/vol2/inference/inference.qmd):Fix: move to lowercase subentries under the existing
Batchingmain entry, per.claude/rules/index.md(Title Case main, lowercase subentries, plain text in keys — no reserved LaTeX chars):This also consolidates three orphan entries under the already-used
Batchingentry for better index navigation.Test plan
grep -rn '\\index{[A-Za-z][A-Za-z0-9]*_[A-Za-z]' book/quarto/contentsreturns zero matches (no other underscore-in-index entries remain book-wide)🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.