Common Error Scenarios and Solutions

This document describes common errors you may encounter when using OhMyG0sh and how to resolve them.

APK Errors
JADX Errors
Configuration Errors
Scan Errors
Pattern Errors
System Errors

APK Errors

APK File Not Found

Error Message:

APK Error: APK file doesn't exist or is not accessible
APK: /path/to/app.apk
Context: Verify the file path and permissions

Causes:

File path is incorrect
File doesn't exist
Insufficient read permissions
File is on unmounted drive

Solutions:

Verify the file exists: ls -la /path/to/app.apk
Check file permissions: chmod 644 /path/to/app.apk
Use absolute path instead of relative path
Ensure the file extension is .apk

Example:

// ❌ Wrong - relative path might be incorrect
final scanner = OhMyG0sh(apkPath: '../app.apk');

// ✅ Correct - use absolute path
final scanner = OhMyG0sh(apkPath: '/home/user/apps/app.apk');

JADX Errors

JADX Not Found

Error Message:

JADX Error: jadx binary not found in PATH
Exit Code: -1
Context: Install jadx using:
  macOS: brew install jadx
  Linux/Windows: https://github.com/skylot/jadx/releases
Or provide explicit path with --jadx option

Causes:

JADX is not installed
JADX is not in system PATH
Wrong JADX path provided

Solutions:

Install JADX:

# macOS
brew install jadx

# Linux (using apt)
sudo apt install jadx

# Manual installation
# Download from https://github.com/skylot/jadx/releases
# Extract and add to PATH

Provide explicit path:

final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  jadxPath: '/usr/local/bin/jadx',
);

Verify installation:
```
which jadx
jadx --version
```

JADX Decompilation Failed

Error Message:

JADX Error: jadx decompilation failed
Exit Code: 1
Context: JADX exited with code 1. Check logs:
  stdout: /tmp/ohmyg0sh-xyz/jadx_stdout.log
  stderr: /tmp/ohmyg0sh-xyz/jadx_stderr.log
Try running with --args "--log-level DEBUG" for more details

Causes:

Corrupted APK file
Unsupported APK format
Obfuscated or protected APK
Insufficient memory
JADX version incompatibility

Solutions:

Check APK integrity:
```
unzip -t app.apk
```

Enable debug logging:

await scanner.run(jadxExtraArgs: ['--log-level', 'DEBUG']);

Continue on errors (if partial results acceptable):

final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  continueOnJadxError: true,  // Default is true
);

Increase memory for large APKs:
```
export JAVA_OPTS="-Xmx4g"
```

Try different JADX options:

await scanner.run(jadxExtraArgs: [
  '--no-res',        // Skip resources
  '--no-imports',    // Don't add imports
  '--deobf',         // Enable deobfuscation
]);

Configuration Errors

Pattern File Not Found

Error Message:

Configuration Error: regexes.json not found in any standard location
File: regexes.json
Searched paths:
  - /app/config/regexes.json
  - /current/dir/config/regexes.json
  - /package/install/config/regexes.json

Solutions:
  1. Provide explicit path with --pattern option
  2. Place regexes.json in ./config/ directory
  3. Ensure package installation is complete

Causes:

Configuration file missing
Wrong working directory
Incomplete package installation
Custom path not provided

Solutions:

Create config directory and file:

mkdir -p config
cp node_modules/ohmyg0sh/config/regexes.json config/

Provide explicit path:

final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  patternPath: '/path/to/custom-patterns.json',
);

Verify package installation:
```
dart pub get
# or
flutter pub get
```

Invalid JSON in Configuration

Error Message:

Configuration Error: Failed to parse configuration file
File: /path/to/regexes.json
Context: Invalid JSON: FormatException: Unexpected character...

Causes:

Malformed JSON syntax
Missing commas or brackets
Invalid escape sequences
UTF-8 encoding issues

Solutions:

Validate JSON:

# Using jq
jq . config/regexes.json

# Using Python
python -m json.tool config/regexes.json

Check common issues:
- Trailing commas (not allowed in JSON)
- Unescaped backslashes in regex patterns
- Missing quotes around keys/values
- Unclosed brackets or braces

Example valid format:

{
  "AWS_Key": "AKIA[0-9A-Z]{16}",
  "API_Token": "(?i)token\\s*[:=]\\s*['\"]([^'\"]+)['\"]"
}

Scan Errors

Too Many Open Files

Error Message:

Scan Error: Too many open files
File: /tmp/ohmyg0sh-xyz/sources/com/example/File.java

Causes:

System file descriptor limit reached
Too high concurrency setting
Large APK with many files

Solutions:

Reduce concurrency:

final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  scanConcurrency: 8,  // Lower value
);

Increase system limits (Unix/Linux):

# Temporary
ulimit -n 4096

# Permanent (add to ~/.bashrc or ~/.zshrc)
echo "ulimit -n 4096" >> ~/.bashrc

Check current limits:
```
ulimit -n
```

File Read Permission Denied

Error Message:

Scan Error: Permission denied
File: /tmp/ohmyg0sh-xyz/sources/protected.java

Causes:

Insufficient permissions on temp directory
SELinux or AppArmor restrictions
Antivirus interference

Solutions:

Check temp directory permissions:
```
ls -la /tmp/ohmyg0sh-*
```
Set proper permissions:
```
chmod -R 755 /tmp/ohmyg0sh-*
```
Use custom temp directory:
```
export TMPDIR=/path/to/writable/temp
```

Pattern Errors

Invalid Regex Pattern

Error Message:

Pattern Error: Invalid regular expression
Pattern Name: Custom_Pattern
Pattern: [invalid(regex
Context: Unterminated character class

Causes:

Malformed regex syntax
Unescaped special characters
Unclosed groups or brackets
Invalid escape sequences

Solutions:

Test regex patterns:

// Test pattern before adding to config
try {
  final regex = RegExp(r'your_pattern_here');
  print('Pattern is valid');
} catch (e) {
  print('Pattern error: $e');
}

Common regex issues:

{
  "❌ Wrong": "[unclosed",
  "✅ Correct": "[a-z]+",
  
  "❌ Wrong": "(unclosed",
  "✅ Correct": "(group)",
  
  "❌ Wrong": "\\invalid",
  "✅ Correct": "\\\\valid"
}

Use online regex testers:
- https://regex101.com/
- https://regexr.com/

System Errors

Out of Memory

Error Message:

Out of memory

Causes:

Large APK file
Insufficient system memory
Memory leak
Too many concurrent operations

Solutions:

Increase Dart VM memory:

dart --old_gen_heap_size=4096 bin/ohmyg0sh.dart -f app.apk

Reduce concurrency:

final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  scanConcurrency: 4,
);

Process in batches:
- Split large APKs if possible
- Scan specific directories only

Disk Space Full

Error Message:

No space left on device

Causes:

Insufficient disk space for decompilation
Temp directory on small partition
Previous temp files not cleaned up

Solutions:

Check disk space:
```
df -h /tmp
```
Clean up old temp files:
```
rm -rf /tmp/ohmyg0sh-*
```

Use different temp directory:

export TMPDIR=/path/to/larger/partition/tmp

Ensure cleanup runs:

try {
  await scanner.run();
} finally {
  await scanner.cleanup();  // Always cleanup
}

Best Practices

Error Handling Pattern

import 'package:ohmyg0sh/ohmyg0sh.dart';

Future<void> scanWithErrorHandling(String apkPath) async {
  final scanner = OhMyG0sh(apkPath: apkPath);
  
  try {
    // Pre-flight checks
    await scanner.integrityCheck();
    print('✓ Pre-flight checks passed');
    
    // Decompile
    await scanner.decompile();
    print('✓ Decompilation complete');
    
    // Scan
    await scanner.scanning();
    print('✓ Scanning complete');
    
    // Generate report
    await scanner.generateReport();
    print('✓ Report generated');
    
  } on ApkError catch (e) {
    print('❌ APK Error: ${e.message}');
    print('   File: ${e.apkPath}');
    if (e.context != null) print('   ${e.context}');
    
  } on JadxError catch (e) {
    print('❌ JADX Error: ${e.message}');
    print('   Exit Code: ${e.exitCode}');
    print('   Recoverable: ${e.isRecoverable}');
    if (e.context != null) print('   ${e.context}');
    
  } on ConfigurationError catch (e) {
    print('❌ Configuration Error: ${e.message}');
    print('   File: ${e.filePath}');
    if (e.context != null) print('   ${e.context}');
    
  } on ScanError catch (e) {
    print('❌ Scan Error: ${e.message}');
    print('   File: ${e.filePath}');
    if (e.context != null) print('   ${e.context}');
    
  } catch (e, stackTrace) {
    print('❌ Unexpected Error: $e');
    print('   Stack Trace: $stackTrace');
    
  } finally {
    // Always cleanup temp files
    await scanner.cleanup();
    print('✓ Cleanup complete');
  }
}

Logging and Debugging

// Enable verbose output
final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  showProgress: true,
);

// Use JADX debug logging
await scanner.run(jadxExtraArgs: ['--log-level', 'DEBUG']);

// Check JADX logs after failure
// Logs are in: /tmp/ohmyg0sh-*/jadx_stdout.log
//              /tmp/ohmyg0sh-*/jadx_stderr.log

CI/CD Configuration

// Fail-fast mode for CI/CD
final scanner = OhMyG0sh(
  apkPath: 'app.apk',
  continueOnJadxError: false,  // Fail on any JADX error
  showProgress: false,          // Silent mode
);

try {
  await scanner.run();
  exit(0);  // Success
} catch (e) {
  print('Scan failed: $e');
  exit(1);  // Failure
}

Getting Help

If you encounter an error not covered here:

Check the logs:
- JADX logs: /tmp/ohmyg0sh-*/jadx_stdout.log
- JADX errors: /tmp/ohmyg0sh-*/jadx_stderr.log

Enable debug mode:

await scanner.run(jadxExtraArgs: ['--log-level', 'DEBUG']);

Report issues:
- GitHub: https://github.com/mathtechstudio/ohmyg0sh/issues
- Include: Error message, APK size, JADX version, OS version
Community support:
- Check existing issues on GitHub
- Search for similar problems
- Provide minimal reproduction example

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Common Error Scenarios and Solutions

Table of Contents

APK Errors

APK File Not Found

JADX Errors

JADX Not Found

JADX Decompilation Failed

Configuration Errors

Pattern File Not Found

Invalid JSON in Configuration

Scan Errors

Too Many Open Files

File Read Permission Denied

Pattern Errors

Invalid Regex Pattern

System Errors

Out of Memory

Disk Space Full

Best Practices

Error Handling Pattern

Logging and Debugging

CI/CD Configuration

Getting Help

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Common Error Scenarios and Solutions

Table of Contents

APK Errors

APK File Not Found

JADX Errors

JADX Not Found

JADX Decompilation Failed

Configuration Errors

Pattern File Not Found

Invalid JSON in Configuration

Scan Errors

Too Many Open Files

File Read Permission Denied

Pattern Errors

Invalid Regex Pattern

System Errors

Out of Memory

Disk Space Full

Best Practices

Error Handling Pattern

Logging and Debugging

CI/CD Configuration

Getting Help