[mmcky]

Upgrades sphinx-exercise from 1.2.1 to 1.2.2 and puts back the figure captions that were removed to keep the PDF build working.

sphinx-exercise 1.2.1 wrote a captioned figure inside an exercise or solution box as a floating \begin{figure}[htbp], which LaTeX rejects there with Not in outer par mode. 1.2.2 writes it as [H], as Sphinx does inside its own admonitions; see executablebooks/sphinx-exercise#94 and executablebooks/sphinx-exercise#95. Until now the workaround was to drop the mystnb figure metadata from code cells inside solutions, as recorded on QuantEcon/meta#297.

Changes

• environment.yml and .github/workflows/collab.yml: sphinx-exercise==1.2.1 → 1.2.2. The release has the same dependencies as 1.2.1, and HTML output is unchanged.
• Restores the caption and name on nine figures, each from a code cell inside a gated solution, exactly as they were before the workaround:

Lecture	Figures	Removed in
exchange_rate_learning	fig-xr-ex4, fig-xr-ex5	#1101
genetic_classifier	fig-gc-bray-ga	#1101
learning_approximation	fig-la-bandwidth, fig-la-rate	#1101
lucas_prescott_search	fig-lps-two-state, fig-lps-undirected, fig-lps-phillips	#1110
information_transfer	fig-it-riley	#1119

Testing

CI's Build PDF from LaTeX step (jb build lectures --builder pdflatex -W --keep-going) is the test. If it passes with the nine captions back, 1.2.2 works on real lectures.

Before merging

lecture-python.zh-cn builds HTML only (its PDF steps are commented out), so the restored captions need no change there; Dependabot will bring its pin to 1.2.2.

Part of QuantEcon/workspace-lectures#70.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WT8bMZoSvoQTbzkdmZiMnd

[Copilot]

Note

Copilot was unable to complete this review at the selected tier due to model policy or plan restrictions.

🔵 Needs a closer look

This change alters PDF build behavior via a dependency upgrade and explicitly requires cross-repo coordination (moving the lecture-python.zh-cn pin first), so a reviewer should verify CI PDF output and downstream sync impacts before approval.

No open issues 🎉

What changed in this PR

Upgrades sphinx-exercise to 1.2.2 to address LaTeX figure placement inside exercise/solution boxes, and restores MyST-NB figure captions/labels for solution-embedded figures so they render correctly again (including in PDF builds).

Changes:

• Bump sphinx-exercise from 1.2.1 to 1.2.2 in the main environment and the Colab workflow.
• Re-add mystnb figure caption/name metadata for 9 figures across 5 lectures (inside gated solutions).

File	Description
lectures/​lucas_prescott_search.md	Restores MyST-NB figure caption/name metadata for three figures produced in gated solution code cells.
lectures/​learning_approximation.md	Restores MyST-NB figure caption/name metadata for two solution-embedded figures.
lectures/​information_transfer.md	Restores MyST-NB figure caption/name metadata for one solution-embedded figure.
lectures/​genetic_classifier.md	Restores MyST-NB figure caption/name metadata for one solution-embedded figure.
lectures/​exchange_rate_learning.md	Restores MyST-NB figure caption/name metadata for two figures inside gated solutions.
environment.yml	Updates the pinned sphinx-exercise version to 1.2.2 in the project environment.
.github/​workflows/​collab.yml	Updates the workflow’s pinned sphinx-exercise version to 1.2.2 in the dependency install step.

_{Review effort: Balanced}

[github-actions]

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Commit: 718ffe1

📚 Changed Lectures

• exchange_rate_learning
• genetic_classifier
• information_transfer
• learning_approximation
• lucas_prescott_search

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Build Info

• Workflow: Build Project [using jupyter-book]