# emerge -vp gcc

These are the packages that would be merged, in order:

Calculating dependencies |

[ Results for search key : gcc ]
*  cross-i686-w64-mingw32/gcc
   ... done!
Traceback (most recent call last):
  File "/usr/lib/python-exec/python2.7/emerge", line 50, in <module>
    retval = emerge_main()
  File "/usr/lib64/python2.7/site-packages/_emerge/main.py", line 1154, in
emerge_main
    return run_action(emerge_config)
  File "/usr/lib64/python2.7/site-packages/_emerge/actions.py", line 3191, in
run_action
    emerge_config.args, spinner)
  File "/usr/lib64/python2.7/site-packages/_emerge/actions.py", line 321, in
action_build
    settings, trees, myopts, myparams, myaction, myfiles, spinner)
  File "/usr/lib64/python2.7/site-packages/_emerge/depgraph.py", line 9117, in
backtrack_depgraph
    myaction, myfiles, spinner)
  File "/usr/lib64/python2.7/site-packages/_emerge/depgraph.py", line 9154, in
_backtrack_depgraph
    success, favorites = mydepgraph.select_files(myfiles)
  File "/usr/lib64/python2.7/site-packages/_emerge/depgraph.py", line 3580, in
select_files
    return self._select_files(args)
  File "/usr/lib64/python2.7/site-packages/_emerge/depgraph.py", line 3799, in
_select_files
    self._frozen_config.spinner, self._frozen_config.myopts)
  File "/usr/lib64/python2.7/site-packages/_emerge/depgraph.py", line 9059, in
ambiguous_package_name
    s.output()
  File "/usr/lib64/python2.7/site-packages/_emerge/search.py", line 407, in
output  
    db.cpv_exists(mycpv):
  File "/usr/lib64/python2.7/site-packages/portage/dbapi/bintree.py", line
116, in cpv_exists
    return fakedbapi.cpv_exists(self, cpv)
  File "/usr/lib64/python2.7/site-packages/portage/dbapi/virtual.py", line
102, in cpv_exists
    support_string=True) in self.cpvdict
  File "/usr/lib64/python2.7/site-packages/portage/dbapi/virtual.py", line 74,
in _instance_key_multi_instance
    raise KeyError(cpv)
KeyError: u'cross-i686-w64-mingw32/gcc-4.7.3-r1'