установка emerge

здравствуйте! такой вопрос - не знаю почему - но при установки любой программы в конце появляется это:

Traceback (most recent call last):
File "/usr/bin/emerge", line 5530, in ?
retval = emerge_main()
File "/usr/bin/emerge", line 5525, in emerge_main
myopts, myaction, myfiles, spinner)
File "/usr/bin/emerge", line 4992, in action_build
retval = mergetask.merge(pkglist, favorites, mtimedb)
File "/usr/bin/emerge", line 3156, in merge
prev_mtimes=ldpath_mtimes)
File "/usr/lib/portage/pym/portage.py", line 3750, in doebuild
vartree=vartree, prev_mtimes=prev_mtimes)
File "/usr/lib/portage/pym/portage.py", line 3958, in merge
mydbapi=mydbapi, prev_mtimes=prev_mtimes)
File "/usr/lib/portage/pym/portage.py", line 7859, in merge
cleanup=cleanup, mydbapi=mydbapi, prev_mtimes=prev_mtimes)
File "/usr/lib/portage/pym/portage.py", line 7490, in treewalk
self.unmerge(oldcontents, trimworld=0, ldpath_mtimes=prev_mtimes)
File "/usr/lib/portage/pym/portage.py", line 7034, in unmerge
contents=contents)
File "/usr/lib/portage/pym/portage.py", line 575, in env_update
myconfig = getconfig(file_path, expand=False)
File "/usr/lib/portage/pym/portage_util.py", line 295, in getconfig
f=open(mycfg,'r')
IOError: [Errno 21] Is a directory

подскажите - как исправить (система работает нормально - проблема с установкой)