Hi, I find it easy to develop libraries using symlinks to git repos. In 1.6.4, symlinks were read correctly. Under 1.6.7, any Windows symlink (Junction points, which are redirecting folder pointers) cause the error, even for a blank sketch:
readlink C:\Users\jimgale\Documents\Arduino\libraries\vsa: The system cannot find the file specified.
(vsa would be the example symlink here pointing to another folder).