You don’t need to add all files in a Grails application- or plugin project to version control, because some of the files are derived (this means they can be re-created from source files) or they are generated for you locally as developer (and have nothing to do with the team) if you use IDEs such as Eclipse or Groovy/Grails Tool Suite (GGTS).

You should ignore the following files in version control:

File or folder Why not in version control?
.project and .classpath Specific IDE (GGTS or Eclipse) generated derivations.
.settings Specific IDE (GGTS or Eclipse) derivations and/or user settings.
target Generated derived classes from sources
target-eclipse Specific IDE (GGTS or Eclipse) generated derived classes from sources

Generated files .project and .classpath contain developer-specific local paths which should not end up in version control. Former versions of Eclipse or GGTS could not deal with the absence of these files, and consequently failed to import any project without these.

Nowadays GGTS is able to detect this and fix it. You’ll get next dialog in this situation:

GGTS Convert to Grails project

By answering Yes, aforementioned files will be re-generated.