React Native: Unable to Fix Module Map Error when building for iOS

Open the file ./ios/Podfile And add these lines inside your targets (right before the use_react_native line in current react-native:

use_frameworks! :linkage => :static
$RNFirebaseAsStaticFramework = true

Also, if you have flipper_configuration Then, commented it out, disable flipper at all.

If it still does not work, check all iOS setup steps carefully from the official doc, https://rnfirebase.io/#configure-firebase-with-ios-credentials-react-native--077

Check below podfile:
try it once.

require_relative '../node_modules/react-native/scripts/react_native_pods'
require_relative '../node_modules/@react-native-community/cli-platform-ios/native_modules'

platform :ios, '13.0'
prepare_react_native_project!

# ✅ Required for Firebase
use_frameworks! :linkage => :static
$RNFirebaseAsStaticFramework = true

target 'MyApp' do
  config = use_native_modules!
  flags = get_default_flags()

  # ✅ Firebase dependencies
  pod 'Firebase', :modular_headers => true
  pod 'FirebaseCore', :modular_headers => true
  pod 'FirebaseCoreInternal', :modular_headers => true
  pod 'FirebaseCoreExtension', :modular_headers => true
  pod 'FirebaseInstallations', :modular_headers => true
  pod 'FirebaseAppDistribution', :modular_headers => true
  pod 'FirebaseCrashlytics', :modular_headers => true
  pod 'FirebaseSessions', :modular_headers => true
  pod 'GoogleDataTransport', :modular_headers => true
  pod 'GoogleUtilities', :modular_headers => true
  pod 'nanopb', :modular_headers => true

  # ✅ Other native modules
  pod 'RNSentry', :podspec => '../node_modules/@sentry/react-native/RNSentry.podspec'
  pod 'react-native-video', :path => '../node_modules/react-native-video/react-native-video.podspec'
  pod 'RNFS', :path => '../node_modules/react-native-fs'
  pod 'react-native-blob-util', :path => '../node_modules/react-native-blob-util'
  pod 'Google-Maps-iOS-Utils', :git => 'https://github.com/Simon-TechForm/google-maps-ios-utils.git', :branch => 'feat/support-apple-silicon'
  pod 'react-native-google-maps', :path => '../node_modules/react-native-maps'

  # ❌ Removed Flipper support completely
  # pod 'react-native-flipper', path: '../node_modules/react-native-flipper'
  # flipper_config = FlipperConfiguration.disabled

  use_react_native!(
    :path => config[:reactNativePath],
    :hermes_enabled => flags[:hermes_enabled],
    :fabric_enabled => flags[:fabric_enabled],
    # ❌ Do not pass :flipper_configuration at all
    :app_path => "#{Pod::Config.instance.installation_root}/.."
  )

  target 'MyApp-Dev' do
    inherit! :complete
  end

  target 'MyApp-Stage' do
    inherit! :complete
  end

  post_install do |installer|
    installer.pods_project.build_configurations.each do |config|
      config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64"
    end

    react_native_post_install(
      installer,
      :mac_catalyst_enabled => false
    )
    __apply_Xcode_12_5_M1_post_install_workaround(installer)

    bitcode_strip_path = `xcrun --find bitcode_strip`.chomp
    def strip_bitcode_from_framework(bitcode_strip_path, framework_relative_path)
      framework_path = File.join(Dir.pwd, framework_relative_path)
      command = "#{bitcode_strip_path} #{framework_path} -r -o #{framework_path}"
      puts "Stripping bitcode: #{command}"
      system(command)
    end

    framework_paths = [
      "Pods/LogRocket/LogRocket.xcframework/ios-arm64/LogRocket.framework/LogRocket",
      "Pods/hermes-engine/destroot/Library/Frameworks/macosx/hermes.framework/hermes",
      "Pods/hermes-engine/destroot/Library/Frameworks/universal/hermes.xcframework/ios-arm64/hermes.framework/hermes"
    ]

    framework_paths.each do |framework_relative_path|
      strip_bitcode_from_framework(bitcode_strip_path, framework_relative_path)
    end
  end
end



# 1. Clean everything
rm -rf ios/Pods ios/Podfile.lock ~/Library/Developer/Xcode/DerivedData

# 2. Install pods again
cd ios && pod install --repo-update

I solved this issue by adding -

1 . source 'https://github.com/CocoaPods/Specs.git' # Use the GitHub spec repo to avoid CDN issues
2. also add 'use_modular_headers!' # so I did not need to mention all file 'modular_headers => true'

NOTE - if it does not work first time then

Cleared cache, deleted derived data, deintegrated pods, removed pods, podfile.lock, build folder, and re-run pod install (and pod install —repo-update).

then build again.

require_relative '../node_modules/react-native/scripts/react_native_pods'
require_relative '../node_modules/@react-native-community/cli-platform-ios/native_modules'

platform :ios, '13.0'
prepare_react_native_project!

# Use the GitHub spec repo to avoid CDN issues
source 'https://github.com/CocoaPods/Specs.git'

# If you are using a `react-native-flipper` your iOS build will fail when `NO_FLIPPER=1` is set.
# because `react-native-flipper` depends on (FlipperKit,...) that will be excluded
#
# To fix this you can also exclude `react-native-flipper` using a `react-native.config.js`
# ```js
# module.exports = {
#   dependencies: {
#     ...(process.env.NO_FLIPPER ? { 'react-native-flipper': { platforms: { ios: null } } } : {}),
# ```
flipper_config = ENV['NO_FLIPPER'] == "1" ? FlipperConfiguration.disabled : FlipperConfiguration.enabled

linkage = ENV['USE_FRAMEWORKS']
if linkage != nil
  Pod::UI.puts "Configuring Pod with #{linkage}ally linked Frameworks".green
  use_frameworks! :linkage => :static
  $RNFirebaseAsStaticFramework = true
end

use_modular_headers!

target 'MyApp' do
  config = use_native_modules!

    # Flags change depending on the env values.
  flags = get_default_flags()
  
  pod 'RNSentry', :podspec => '../node_modules/@sentry/react-native/RNSentry.podspec'
  pod 'react-native-flipper', path: '../node_modules/react-native-flipper'
  pod 'react-native-video', :path => '../node_modules/react-native-video/react-native-video.podspec'
  pod 'Firebase'
  pod 'FirebaseCore'
  pod 'FirebaseCoreInternal'
  pod 'FirebaseCoreExtension'
  pod 'FirebaseInstallations'
  pod 'GoogleDataTransport'
  pod 'nanopb'
  pod 'GoogleUtilities'
  pod 'Google-Maps-iOS-Utils', :git => 'https://github.com/Simon-TechForm/google-maps-ios-utils.git', :branch => 'feat/support-apple-silicon'
  pod 'RNFS', :path => '../node_modules/react-native-fs'
  pod 'react-native-blob-util',
    :path => '../node_modules/react-native-blob-util'

  rn_maps_path = '../node_modules/react-native-maps'
  pod 'react-native-google-maps', :path => rn_maps_path

  config = use_native_modules!

  use_react_native!(
    :path => config[:reactNativePath],
    # Hermes is now enabled by default. Disable by setting this flag to false.
    # Upcoming versions of React Native may rely on get_default_flags(), but
    # we make it explicit here to aid in the React Native upgrade process.
    :hermes_enabled => flags[:hermes_enabled],
    :fabric_enabled => flags[:fabric_enabled],
    # Enables Flipper.
    #
    # Note that if you have use_frameworks! enabled, Flipper will not work and
    # you should disable the next line.
    :flipper_configuration => flipper_config,
    # An absolute path to your application root.
    :app_path => "#{Pod::Config.instance.installation_root}/.."
  )

  target 'MyApp-Dev' do
    inherit! :complete
    # Pods for testing
  end

  target 'MyApp-Stage' do
    inherit! :complete
    # Pods for testing
  end

  post_install do |installer|
    installer.pods_project.build_configurations.each do |config|
      config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64"
    end
    react_native_post_install(
      installer,
      # Set `mac_catalyst_enabled` to `true` in order to apply patches
      # necessary for Mac Catalyst builds
      :mac_catalyst_enabled => false
    )
    __apply_Xcode_12_5_M1_post_install_workaround(installer)

    bitcode_strip_path = `xcrun --find bitcode_strip`.chop!
    def strip_bitcode_from_framework(bitcode_strip_path, framework_relative_path)
      framework_path = File.join(Dir.pwd, framework_relative_path)
      command = "#{bitcode_strip_path} #{framework_path} -r -o #{framework_path}"
      puts "Stripping bitcode: #{command}"
      system(command)
    end

    framework_paths = [
      "Pods/LogRocket/LogRocket.xcframework/ios-arm64/LogRocket.framework/LogRocket",
      "Pods/hermes-engine/destroot/Library/Frameworks/macosx/hermes.framework/hermes",
      "Pods/hermes-engine/destroot/Library/Frameworks/macosx/hermes.framework/Versions/Current/hermes",
      "Pods/hermes-engine/destroot/Library/Frameworks/universal/hermes.xcframework/ios-arm64/hermes.framework/hermes",
      "Pods/hermes-engine/destroot/Library/Frameworks/universal/hermes.xcframework/ios-arm64_x86_64-maccatalyst/hermes.framework/hermes"
    ]

    framework_paths.each do |framework_relative_path|
      strip_bitcode_from_framework(bitcode_strip_path, framework_relative_path)
    end
  end
end