问题
I came across this error when trying to build an ionic project for ios. It happened in the FirebaseCore build part of the process.
I found the problem was a bug in the following file on line 23:
platforms/ios/Pods/FirebaseCore/Firebase/Core/FIRNetwork.m
It seems the angle brackets don't allow the search for the file to start at the Pods level, whereas quotes allow a relative path to be used.
I found the solution was to do the following, so I thought I'd post it here in case anyone else has the same problem:
Either:
Change line 23 from:
#import <GoogleToolboxForMac/GTMNSData+zlib.h>
to:
#import "../../../GoogleToolboxForMac/Foundation/GTMNSData+zlib.h"
Or:
Add the following to the end of the Header Search Paths setting your Xcode project Build Settings:
"${PODS_ROOT}"
来源：https://stackoverflow.com/questions/51636994/cannot-find-googletoolboxformac-gtmnsdatazlib-h-error-when-building-an-ionic