Jenkis creates files instead of symlinks when deploying

I actually have a weird issue with Jenkins and 2 PHP project. When deploying before launching the test suite, instead of having correct symlinks, Jenkins create files containing the target path of the symlinks. What I don't understand is that is doesn't work only on 2 projects. It's OK one another very similar one. I tried to delete the working directories of those 2 projects but I've got the same result. Any hint would be appreciated.