Error

[!] CocoaPods did not set the base configuration of your project because your project already has a custom config set. In order for CocoaPods integration to work at all, please either set the base configurations of the target `Runner` to `Target Support Files/Pods-Runner/Pods-Runner.profile.xcconfig` or include the `Target Support Files/Pods-Runner/Pods-Runner.profile.xcconfig` in your build configuration (`Flutter/Release.xcconfig`).

Solution

root/ios/Flutter/Release.xcconfig에 다음 줄 추가

#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.profile.xcconfig"