I am building a Spring Boot application using Gradle as the build engine. I had something odd occur when I added a dependency to build.gradle. All of my External Libraries disappeared with the exception of my Java libraries. I reverted to my original build.gradle but I couldn't get the External Libraries back. I had to copy my source code to a new workspace. I figured that my changes to build.gradle caused an error that caused my External Libraries to be removed. However, shouldn't I have been able to rebuild the external libraries once I reverted to the original build.gradle?