# Critique of PR #13829: Update build documentation with quick build optimization flags

## Introduction & Diátaxis Context

This review uses the Diátaxis documentation framework (Tutorials, How-To Guides, Reference, Explanation) to analyze PR #13829. All section/file references are to the final version of PR #5218, unless otherwise specified.

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## 1. Tutorials

**Expectation:** Step-by-step, learning-focused introductions for new users.

**Findings in PR #13829:**  
- The new PR introduces QUICK_REBUILD flags, but lacks a complete, guided build scenario for first-time contributors.
- In PR #5218, `toolkit/docs/building/building.md`, section “Quick Start” (lines 10–42), provides a clear walkthrough for new users, including environment setup, initial build, and verifying output. 
- Also in the same file, section “Building Your First Package” (lines 60–105) gives a practical example of building a package from scratch, illustrating the effect of build flags.

**Recommendation:**  
- Restore or adapt the “Quick Start” and “Building Your First Package” sections from PR #5218.
- Provide a boxed, narrative tutorial at the top of the build documentation, walking the user through a build with and without QUICK_REBUILD.

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## 2. How-To Guides

**Expectation:** Task-oriented recipes for real-world scenarios.

**Findings in PR #13829:**  
- The documentation lists the new flags, but omits practical, scenario-based guidance.
- In PR #5218, see `toolkit/docs/building/building.md`, section “How to Avoid Unnecessary Toolchain Rebuilds” (lines 340–375), for actionable steps to prevent accidental full toolchain rebuilds, including an explanation of stable tags.
- Section “Troubleshooting Delta Builds” (lines 380–400) covers recovery when quick build flags misfire.

**Recommendation:**  
- Reintroduce these “How-To” sections, with explicit command-line examples and step-by-step solutions.
- Add a scenario: “If you set QUICK_REBUILD_TOOLCHAIN=y and experience slow builds, check your use of stable tags as described in the ‘How to Avoid Unnecessary Toolchain Rebuilds’ section.”

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## 3. Reference

**Expectation:** Exhaustive, precise documentation of all build flags and variables.

**Findings in PR #13829:**  
- The list and matrix of flags is less complete than in PR #5218.
- In PR #5218, see `toolkit/docs/building/building.md`, section “Toolkit Build Flags Reference” (table on lines 220–260), for a matrix of all relevant build flags, possible values, defaults, and effects.
- The older PR also includes notes on flag interactions and edge cases (lines 270–295).

**Recommendation:**  
- Restore and update the detailed reference table.
- For each QUICK_REBUILD flag, ensure all possible values, defaults, and interactions are described.
- Add “See also” references to related troubleshooting and how-to sections.

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## 4. Explanation

**Expectation:** Concepts, rationale, and consequences.

**Findings in PR #13829:**  
- There is little conceptual explanation of why quick rebuild flags exist, their architectural impact, or the risks of misusing QUICK_REBUILD_TOOLCHAIN.
- In PR #5218, see `toolkit/docs/building/building.md`, section “Background: Why Use Stable Tags?” (lines 310–325), for rationale and best practices.
- Section “What Happens During a Toolchain Rebuild?” (lines 330–339) explains the risks and consequences of full toolchain rebuilds.

**Recommendation:**  
- Reintroduce or adapt these “Explanation” sections, making clear the risks and best practices around toolchain and package rebuilds.
- Explicitly discuss why stable tags matter and how they interact with QUICK_REBUILD flags.

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## Concrete References from PR #5218

- **Tutorials:**  
  - `toolkit/docs/building/building.md`, “Quick Start” (lines 10–42)
  - `toolkit/docs/building/building.md`, “Building Your First Package” (lines 60–105)

- **How-To Guides:**  
  - `toolkit/docs/building/building.md`, “How to Avoid Unnecessary Toolchain Rebuilds” (lines 340–375)
  - `toolkit/docs/building/building.md`, “Troubleshooting Delta Builds” (lines 380–400)

- **Reference:**  
  - `toolkit/docs/building/building.md`, “Toolkit Build Flags Reference” (lines 220–260)
  - `toolkit/docs/building/building.md`, flag interactions and notes (lines 270–295)

- **Explanation:**  
  - `toolkit/docs/building/building.md`, “Background: Why Use Stable Tags?” (lines 310–325)
  - `toolkit/docs/building/building.md`, “What Happens During a Toolchain Rebuild?” (lines 330–339)

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## Summary & Next Steps

PR #13829 makes valuable updates, but omits much of the instructional, practical, and conceptual depth from PR #5218. To align with the Diátaxis model and maintain documentation quality:
- Expand Tutorials with step-by-step, beginner guides.
- Add practical How-To Guides, especially for avoiding toolchain rebuilds.
- Restore exhaustive Reference tables and notes.
- Reintroduce Explanation sections on rationale and consequences.

Addressing these points will ensure the documentation is both complete and genuinely useful for all users.

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