rpmdb open failed on fedora 12

$ sudo yum clean all
rpmdb: Thread/process 3269/3078403776 failed: Thread died in Berkeley DB library
error: db4 error(-30974) from dbenv->failchk: DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db3 - (-30974)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:

Error: rpmdb open failed

i got this error after failing to yum install anything, the process seems to be stuck so i just cancelled it. my second attempt to yum clean all gave me the above error

a quick googling brought me here and all i have to do is just rebuild all rpmdb.

# rm /var/lib/rpm/__db*
# rpm --rebuilddb
# yum clean all

after rebuilding rpmdb, i tried yum search something and the previous problem seems to be caused by chromium repo. so i just disable the repo, and everything works as usual :)