axiom-auto-layout-debugging

# Auto Layout Debugging

## When to Use This Skill

Use when:
- Seeing "Unable to simultaneously satisfy constraints" errors in console
- Views positioned incorrectly or not appearing
- Constraint warnings during app launch or navigation
- Ambiguous layout errors
- Views appearing at unexpected sizes
- Debug View Hierarchy shows misaligned views
- Storyboard/XIB constraints behaving differently at runtime

## Overview

**Core Principle**: Auto Layout constraint errors follow predictable patterns. Systematic debugging with proper tools identifies issues in minutes instead of hours.

**Time Savings**: Typical constraint debugging without this workflow: 30-60 minutes. With systematic approach: 5-10 minutes.

---

## Quick Decision Tree

```
Constraint error in console?
├─ Can't identify which views?
│  └─ Use Symbolic Breakpoint + Memory Address Identification
├─ Constraint conflicts shown?
│  └─ Use Constraint Priority Resolution
├─ Ambiguous layout (multiple solutions)?
│  └─ Use _autolayoutTrace to find missing constraints
└─ Views positioned incorrectly but no errors?
   └─ Use Debug View Hierarchy + Show Constraints
```

---

## Understanding Constraint Error Messages

### Anatomy of Error Message

```
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list you don't need.

(
    "<NSLayoutConstraint:0x7f8b9c6...  'UIView-Encapsulated-Layout-Width' ... (active)>",
    "<NSLayoutConstraint:0x7f8b9c5...  UILabel:0x7f8b9c4... .width == 300   (active)>",
    "<NSLayoutConstraint:0x7f8b9c3...  UILabel:0x7f8b9c4... .leading == ... + 20   (active)>",
    "<NSLayoutConstraint:0x7f8b9c2...  ... .trailing == UILabel:0x7f8b9c4... .trailing + 20   (active)>"
)

Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f8b9c5... UILabel:0x7f8b9c4... .width == 300   (active)>
```

**Key Components**:
1. **Memory addresses** — `0x7f8b9c4...` identifies views and constraints
2. **Visual Format** — Human-readable con