If you’re an iOS developer or a Flutter enthusiast, you’ve likely stumbled across this frustrating error: “BoringSSL-GRPC unsupported option ‘-G’ for target ‘arm64-apple-ios15.0′”. It’s a mouthful, right? And it’s even more annoying when it stops your app from building in Xcode. Don’t worry—I’ve got you covered! In this expert guide, I’ll break down what this error means, why it happens, and how to fix it step-by-step in 2025. Plus, I’ll sprinkle in some SEO magic to make sure you (and others) can find this solution easily.
Table of Contents
What Does “BoringSSL-GRPC Unsupported Option ‘-G'” Mean?
First things first—what’s going on here? This error shows up when you’re trying to build an iOS app (often with Flutter, React Native, or Firebase) and the compiler (Clang, in this case) freaks out. It’s telling you that the -G flag isn’t supported for the target architecture arm64-apple-ios15.0. But wait—-G? What’s that?
Breaking It Down
- BoringSSL: A Google-maintained version of OpenSSL, used for secure communication (think HTTPS and TLS).
- GRPC: A high-performance framework for remote procedure calls, often paired with BoringSSL for networking.
- ‘-G’ Flag: This isn’t actually a standalone flag. It’s a misinterpretation of
-GCC_WARN_INHIBIT_ALL_WARNINGS, a compiler setting meant to silence warnings. In Xcode 16 and later, Clang doesn’t like it and throws this error. - arm64-apple-ios15.0: The target platform—Apple’s 64-bit architecture for iOS 15.0 devices (like iPhones or iPads).
So, the root cause? A mismatch between an outdated BoringSSL-GRPC setup and modern Xcode versions (like Xcode 16 in 2025). Let’s explore why this happens and how to fix it.
Why Does This Error Happen in 2025?
As of March 31, 2025, iOS development has evolved fast. Xcode 16, paired with macOS updates like Sequoia, brought changes to how Clang handles compiler flags. The -GCC_WARN_INHIBIT_ALL_WARNINGS flag, used in older BoringSSL-GRPC podspecs, isn’t recognized properly anymore. Instead, Clang sees it as -G and crashes the build.
Common Triggers
- Xcode Update: Upgrading to Xcode 16 or later (common in 2025) exposes this issue.
- Old Dependencies: If your project uses an outdated version of BoringSSL-GRPC (like 0.0.24), it’s not compatible with new tools.
- Flutter/React Native: These frameworks often bundle Firebase, which relies on BoringSSL-GRPC, amplifying the problem.
- Podfile Misconfig: Your CocoaPods setup might not account for the latest build requirements.
The good news? It’s fixable! Let’s roll up our sleeves and get to work.
How to Fix BoringSSL-GRPC Unsupported Option ‘-G’ Error
Here’s your step-by-step playbook to squash this bug. I’ll give you multiple solutions—pick the one that fits your setup. Short paragraphs and bullet points ahead for easy reading!
Solution 1: Update Your Dependencies
The simplest fix? Update everything. Old versions of BoringSSL-GRPC (pre-0.0.32) are the main culprits.
Steps:
- Check Your Podfile: Open your
ios/Podfileand look forBoringSSL-GRPC. - Update CocoaPods: Run this in your terminal:
cd ios
pod update- Force Latest Version: If it’s still old, specify a newer version explicitly:
pod 'BoringSSL-GRPC', '~> 0.0.32'- Clean & Rebuild: Clear the build cache and reinstall:
pod deintegrate
pod cache clean --all
pod installWhy It Works:
Newer BoringSSL-GRPC versions ditch the problematic flag, aligning with Xcode 16’s Clang updates.
Solution 2: Modify the Podfile (Quick Fix)
If updating isn’t an option (maybe you’re stuck with a specific version), tweak your Podfile to strip out the -G flag manually.
Steps:
- Open Podfile: Navigate to
ios/Podfile. - Add This Code: At the bottom, insert this post-install hook:
post_install do |installer|
installer.pods_project.targets.each do |target|
if target.name == 'BoringSSL-GRPC'
target.source_build_phase.files.each do |file|
if file.settings && file.settings['COMPILER_FLAGS']
flags = file.settings['COMPILER_FLAGS'].split
flags.reject! { |flag| flag == '-GCC_WARN_INHIBIT_ALL_WARNINGS' }
file.settings['COMPILER_FLAGS'] = flags.join(' ')
end
end
end
target.build_configurations.each do |config|
config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '15.0'
end
end
end- Reinstall Pods: Run:
pod install- Build Again: Open Xcode and hit build!
Why It Works:
This script finds every file in BoringSSL-GRPC, removes the offending flag, and ensures your deployment target matches iOS 15.0 or higher.
Solution 3: Upgrade Firebase (For Flutter Users)
Using Flutter with Firebase? Older Firebase versions pull in outdated BoringSSL-GRPC. Upgrade to Firebase 10.27.0 or later.
Steps:
- Update pubspec.yaml:
dependencies:
firebase_core: ^2.24.0
cloud_firestore: ^5.0.0- Run Flutter Commands:
flutter pub get
cd ios
pod update- Clean Build:
flutter clean
flutter runWhy It Works:
Newer Firebase SDKs use updated BoringSSL-GRPC, dodging the -G issue entirely.
Solution 4: Adjust Xcode Build Settings
If the above don’t work, tweak Xcode directly to bypass the flag.
Steps:
- Open Project in Xcode: Load
Runner.xcworkspacefrom youriosfolder. - Find BoringSSL-GRPC: In the Pods project, locate the
BoringSSL-GRPCtarget. - Edit Build Settings:
- Search for
GCC_WARN_INHIBIT_ALL_WARNINGS. - Set it to
NOor delete it.
- Build Again: Clean (Cmd+Shift+K) and rebuild.
Why It Works:
Manually removing the flag at the source stops Clang from misreading it as -G.
Preventing This Error in the Future
Fixed it? Awesome! Now, let’s keep it from coming back in 2025 and beyond.
- Stay Updated: Regularly update Xcode, CocoaPods, and dependencies.
- Monitor Deprecations: Check release notes for tools like Firebase or GRPC.
- Test on Betas: Try new Xcode betas early to catch issues like this.
- Backup Podfile: Save a working version before tinkering.
FAQs About BoringSSL-GRPC ‘-G’ Error
Why does this only happen with Xcode 16?
Xcode 16’s Clang update changed how it parses flags, breaking compatibility with older BoringSSL-GRPC settings.
Can I ignore this error?
Nope—it halts your build. You’ve got to fix it to ship your app.
Does this affect Android builds?
No, this is iOS-specific, tied to Xcode and Clang.
What if none of these fixes work?
Check your deployment target (bump it to 15.0+ if lower) or reach out on Stack Overflow with your Podfile.
Conclusion: Master Your iOS Builds in 2025
The “BoringSSL-GRPC unsupported option ‘-G’ for target ‘arm64-apple-ios15.0′” error might seem like a roadblock, but it’s just a bump in the road. With the fixes above—updating dependencies, tweaking your Podfile, or adjusting Xcode—you’ll be back to building slick iOS apps in no time. As an expert tip, always keep your tools fresh to avoid these hiccups.
Got questions or a unique case? Drop a comment below.