title: Why it shows "ld: framework not found Bolts"
body: <p>After I install facebook sdk, when I build my project, it shows:</p>
  <pre><code>ld: warning: directory not found for option '-F/Users/liyuanliu/Library/Developer/Xcode/DerivedData/c5-dsovqtraubbdgxbqrmiexjmlysxq/Build/Products/Debug-iphonesimulator/Bolts'
  ld: warning: directory not found for option '-F/Users/liyuanliu/Library/Developer/Xcode/DerivedData/c5-dsovqtraubbdgxbqrmiexjmlysxq/Build/Products/Debug-iphonesimulator/FBSDKCoreKit'
  ld: warning: directory not found for option '-F/Users/liyuanliu/Library/Developer/Xcode/DerivedData/c5-dsovqtraubbdgxbqrmiexjmlysxq/Build/Products/Debug-iphonesimulator/FBSDKLoginKit'
  ld: warning: directory not found for option '-F/Users/liyuanliu/Library/Developer/Xcode/DerivedData/c5-dsovqtraubbdgxbqrmiexjmlysxq/Build/Products/Debug-iphonesimulator/FBSDKShareKit'
  ld: framework not found Bolts
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  <p>But when I install facebook and bolts, it shows I install them successfully:</p>
  <pre><code>pod install
  Analyzing dependencies
  Downloading dependencies
  Using Bolts (1.8.4)
  Using FBSDKCoreKit (4.14.0)
  Using FBSDKLoginKit (4.14.0)
  Using FBSDKShareKit (4.14.0)
  Using Firebase (3.4.0)
  Using FirebaseAnalytics (3.3.0)
  Using FirebaseAppIndexing (1.0.4)
  Using FirebaseAuth (3.0.4)
  </code></pre>
  <p>Below is my build phases image :</p>
  <p><a href="https://i.stack.imgur.com/futty.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/futty.png" alt="enter image description here" /></a></p>
  <p>And below cannot find bolts framework image</p>
  <p><a href="https://i.stack.imgur.com/8WBhk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8WBhk.png" alt="enter image description here" /></a></p>
  <p>I cannot find the <code>FBXXXX.framework</code>
  <a href="https://i.stack.imgur.com/WnezB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WnezB.png" alt="enter image description here" /></a></p>
  <p>After I add frameworks, it still exits:
  <a href="https://i.stack.imgur.com/DSZcQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DSZcQ.png" alt="enter image description here" /></a></p>