Code-signing issue. Getting a Build failed, with no specific error
Take a look at the build log. This will show the error causing the build to be marked as failed.


  Xcode > View (menu) > Navigators > Show Log Navigator


Within the log navigator, click on the last build. You will be presented with the build steps; control-click on one of the steps and select Expand All Transcripts.

At this point, you will see everything the build system did and the output from each command. The error will be within this text.