Xcode error: library not found for -lGoogleToolboxForMac
<p>I am trying to install admobs in my iPhone App (written in objective-c).  I have implemented this many times using swift projects, but currently I keep getting the following build error:</p>

<pre><code>ld: warning: directory not found for option '-L/Users/charlieseligman/Library/Developer/Xcode/DerivedData/ThamesClippers-csissodainpbbjenykdyxuutzxtg/Build/Products/Debug-iphonesimulator/GoogleToolboxForMac'
ld: warning: directory not found for option '-L/Users/charlieseligman/Documents/GIT/iOS.ThamesClippers/build/Debug-iphoneos/GoogleToolboxForMac'
ld: library not found for -lGoogleToolboxForMac
clang: error: linker command failed with exit code 1 (use -v to see invocation)
</code></pre>

<p>I am definitely opening the .xcworkspace file (and not the .xcodeproj file).</p>

<p>I have also tried deleting 'DerivedData' folder contents &amp; 'Cleaning' the project and doing a 'Clean Build Folder'. None has resolved the issue.</p>

<p>My podfile only includes the following pods:</p>

<pre><code># Pods for ThamesClippers
pod 'Google/Analytics'
pod 'Firebase/Core'
pod 'Firebase/AdMob'

# Trying to fix GoogleToolboxForMac missing error
pod 'Firebase/Messaging'
pod 'GoogleToolboxForMac/Logger' 
pod 'GoogleToolboxForMac', '~&gt; 2.1'
</code></pre>

<p>I have tried adding the bottom 3 one-by-one but kept getting the same build error.</p>

<p>Can anyone help?  At a complete loss on this one.  Seen these two questions but their accepted solutions have not resolved this issue:</p>

<p><a href="https://stackoverflow.com/questions/40358719/framework-not-found-googletoolboxformac">Framework not found GoogleToolboxForMac</a>
<a href="https://stackoverflow.com/questions/40848656/ld-library-not-found-for-lgoogletoolboxformac">ld: library not found for -lGoogleToolboxForMac</a></p>