[!] Pas de podSpec trouvé pour package_name dans path_to_package ...

// Flutter and Dart : IOS Specific! IOS only!!!
// Error Message :
"[!] No podspec found for package_name in path_to_package..."

// Step 1 - podfile.lock and PODS folder are generated when you run pod install
Delete File -> "podfile.lock"
Delete Folder -> "PODS"

// Step 2 - Open you project directory root in your terinal and run :
// This command will fetch your packages.
flutter pub get

// Step 3 - cd into your flutter ios folder and run : 
// This will install your packages. Should fix your problem. 
pod install
13Garth