title: iOS Simulator launch fails when specifying each flavor a different $(PRODUCT_BUNDLE_IDENTIFIER)
body: <p>After configuring multiple flavors for my flutter app, compiling and installing to iOS Simulator succeeds. But the final step of launching the app fails with the following error:
  <code>$(PRODUCT_BUNDLE_IDENTIFIER)" is unknown to FrontBoard</code>
  Each .xcconfig file for the flavor has the following entry with unique bundle identifier.
  <code>PRODUCT_BUNDLE_IDENTIFIER=Flavor</code></p>
  
  <p>Seems like compile time PRODUCT_BUNDLE_IDENTIFIER is resolved successfully but somehow launching procedure fails.</p>
  
  <p>Hardcoding the bundle identifier to the project also does not work well, the first bundle identifier is always used to launch the app.</p>
  
  <p>The project is configured as below:
  <a href="https://i.stack.imgur.com/nr0QR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nr0QR.png" alt="Project"></a></p>
  
  <pre><code>ProcessException: Process "/usr/bin/xcrun" exited abnormally:
  $(PRODUCT_BUNDLE_IDENTIFIER): -1
  
  An error was encountered processing the command (domain=FBSOpenApplicationServiceErrorDomain, code=1):
  The request to open "$(PRODUCT_BUNDLE_IDENTIFIER)" failed.
  The request was denied by service delegate (SBMainWorkspace) for reason: NotFound ("Application
  "$(PRODUCT_BUNDLE_IDENTIFIER)" is unknown to FrontBoard").
  Underlying error (domain=FBSOpenApplicationErrorDomain, code=4):
      The operation couldn’t be completed. Application "$(PRODUCT_BUNDLE_IDENTIFIER)" is unknown to
      FrontBoard.
      Application "$(PRODUCT_BUNDLE_IDENTIFIER)" is unknown to FrontBoard.
    Command: /usr/bin/xcrun simctl launch 000D67C7-91CE-48E4-A73B-93E69F888255
    $(PRODUCT_BUNDLE_IDENTIFIER) --enable-dart-profiling --enable-checked-mode --verify-entry-points
    --observatory-port=0
  Error launching application on iPhone Xs.
  </code></pre>
  
  <p>How to make this work?</p>