Fix RCTDefines.h File Not Found in React Native (Xcode)

Originally published on PEAKIQ

Source: https://www.peakiq.in/blog/fix-react-rctdefines-h-file-not-found-in-react-native-multiple-commands-produce

---

---

Fix: "Multiple commands produce" error

Warning: This fix targets RNWifi specifically. Your case may differ —
verify against the original source if your target name or project structure is different.

When Xcode throws a "Multiple commands produce" error in a React Native project, it typically means two build targets are competing to output the same file. The most common culprit is RNWifi. This guide walks through both the Xcode-side fix and the Podfile patch needed to fully resolve it.

---

Part 1 — Xcode Configuration

Open your project's .xcworkspace file in Xcode, then follow these steps:

1. Navigate to the RNWifi library

In the Project Navigator (left sidebar), expand:

Libraries → RNWifi.xcodeproj

2. Open Build Settings

Click on RNWifi.xcodeproj, go to the Build Settings tab, and under Targets select the first target in the list.

3. Add the Header Search Path

Scroll to Search Paths → Header Search Paths and add:

${SRCROOT}/../../../ios/Pods/Headers

Set the path type to recursive.

---

Part 2 — Podfile Fix

Open your ios/Podfile and replace the post_install block with the following. This explicitly removes the duplicate targets (React and RNWifi) that trigger the Xcode conflict and enforces a consistent iOS deployment target across all remaining pods.

use_flipper!
post_install do |installer|
  react_native_post_install(installer)
  __apply_Xcode_12_5_M1_post_install_workaround(installer)

  installer.pods_project.targets.each do |target|
    # Remove conflicting targets — RNWifi causes the duplicate
    targets_to_ignore = %w(React RNWifi)
    if targets_to_ignore.include?(target.name)
      target.remove_from_project
      next
    end

    # Enforce minimum iOS deployment target for all other pods
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.0'
    end
  end
end

Key lines explained:

Line	Purpose
targets_to_ignore	Lists targets to strip from the Pods project
remove_from_project	Removes the target entirely before the build runs
IPHONEOS_DEPLOYMENT_TARGET	Silences deployment target warnings on remaining pods

---

Part 3 — Final Steps

From your project root, re-install pods:

cd ios && pod install

Then in Xcode, clean and rebuild:

Action	Shortcut
Clean build folder	⌘ Shift K
Rebuild	⌘ B

The error should be gone after a clean rebuild.

---

Troubleshooting

Error persists after pod install?
Wipe the Pods cache entirely and reinstall:

rm -rf ios/Pods ios/Podfile.lock
cd ios && pod install

Different library causing the conflict?
Add it to the ignore list using the same pattern:

targets_to_ignore = %w(React RNWifi YourConflictingLib)