Your bug report

#18266: grep -P and invalid exits with error 

which was filed against the grep package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 18266@debbugs.gnu.org.

-- 
18266: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=18266
GNU Bug Tracking System
Contact help-debbugs@gnu.org with problems