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# Circular Import Validator Error Handling Improvements

## Overview
Enhanced error handling in `scripts/validate.py` for the circular import validator to provide comprehensive error coverage, actionable guidance, and better user experience.

## Improvements Implemented

### 1. Enhanced Error Detection
Added specific exception handlers for:
- **ModelOnexError**: Path validation and configuration errors
- **PermissionError**: File system permission issues
- **AttributeError**: API version incompatibilities
- **Generic Exception**: Catch-all for unexpected errors

### 2. Actionable Error Messages
All error messages now include:
- Clear description of the problem
- "Fix:" section with specific remediation steps
- Relevant context (paths, commands, etc.)

### 3. Improved Output Display

#### Verbose Mode (`--verbose`)
- Shows ALL import errors (not limited to 5)
- Displays complete error details
- Includes module names and error messages
- Shows both import_errors and unexpected_errors

#### Non-Verbose Mode (default)
- Shows limited errors (max 5) to avoid clutter
- Includes hint to use `--verbose` for more details
- Still shows critical information (success/failure counts)

#### Always Shown
- Import validation summary (succeeded/failed counts)
- Success rate percentage
- Total files analyzed
- Circular import cycles (if found) with fix suggestions

### 4. Enhanced Circular Import Detection

When circular imports are found:
```
Circular import cycles detected:
  - module1 -> module2 -> module1
  ... and N more

Fix: Break circular dependencies by:
  1. Moving shared code to a common module
  2. Using TYPE_CHECKING imports for type hints
  3. Restructuring module dependencies
```

### 5. Import Error Diagnostics

Shows import errors even when no circular imports exist:
```
Import validation: 0 succeeded, 21 failed
Module import errors (may indicate missing dependencies):
  - clients: No module named 'clients'
  - nodes: No module named 'nodes'
  ... and 16 more (use --verbose for all)
```

## Error Handling Coverage

### Configuration Errors (ModelOnexError)
**Scenario**: Invalid source path, non-existent directory
```
Imports: ERROR (Configuration error: [ONEX_CORE_006_VALIDATION_ERROR] Source path does not exist: /path)
  Fix: Verify source path exists and is readable: /path
```
**Result**: Fails validation (returns False)

### Missing Dependencies (ImportError)
**Scenario**: omnibase_core not installed
```
Imports: SKIP (CircularImportValidator not available: No module named 'omnibase_core')
  Fix: Install omnibase_core with: uv add omnibase-core
```
**Result**: Skips validation (returns True) - doesn't fail build

### API Incompatibility (AttributeError)
**Scenario**: Version mismatch between omnibase_infra and omnibase_core
```
Imports: ERROR (Validator API incompatible: 'ModelValidationResult' object has no attribute 'total_files')
  Fix: Update omnibase_core to compatible version
    uv add --upgrade omnibase-core
    or check omnibase_core version requirements
```
**Result**: Fails validation (returns False) - integration bug must be fixed

### Permission Issues (PermissionError)
**Scenario**: No read access to source directory
```
Imports: ERROR (Permission denied: [Errno 13] Permission denied: '/path')
  Fix: Ensure read permissions for: /path
```
**Result**: Fails validation (returns False)

### Unexpected Errors (Exception)
**Scenario**: Bugs in validator, unexpected file structures
```
Imports: ERROR (Unexpected RuntimeError: unexpected error message)
  This may indicate a bug in the validator or unexpected file structure
  Fix: Report this error with full output if it persists
```
**Result**: Fails validation (returns False) - may hide real bugs

## Usage Examples

### Check for circular imports (quiet mode)
```bash
uv run python scripts/validate.py imports
```

### Check with full error details
```bash
uv run python scripts/validate.py imports --verbose
```

### Run all validators including imports
```bash
uv run python scripts/validate.py all --verbose
```

### Quick validation (skip imports)
```bash
uv run python scripts/validate.py all --quick
```

## Benefits

1. **Comprehensive Coverage**: All error scenarios properly handled
2. **Actionable Guidance**: Users know exactly what to do when errors occur
3. **Better Debugging**: Verbose mode provides complete error context
4. **User-Friendly**: Clear, concise error messages with fix suggestions
5. **Robust**: No cryptic errors or silent failures
6. **CI/CD Ready**: Proper exit codes for automated testing

## Testing

All improvements verified through:
- ✅ Unit tests (33 tests pass)
- ✅ Integration testing with real validator
- ✅ Error scenario testing (ModelOnexError, etc.)
- ✅ Verbose/non-verbose output verification
- ✅ Full validation suite execution

## Related Files

- `scripts/validate.py` (lines 135-224) - Main implementation
- `src/omnibase_infra/validation/infra_validators.py` - Validator wrappers
- `tests/unit/validation/test_validator_defaults.py` - Test coverage
