Ultimately, I rebooted after all this. I then found that root and user were able to query the database and install rpms again. At this point I don't know if my repeated --rebuilddb attempts actually worked but stalled before closing the process or what, but it is working again for now.
Most probably the database was locked by an rpm -Va issued by msec
Bye -- Luca Olivetti Note.- This message reached you today, it may not tomorrow if you are using MAPS or other RBL. They arbitrarily IP addresses not related in any way to spam, disrupting Internet connectivity. See http://slashdot.org/article.pl?sid=01/05/21/1944247 and http://theory.whirlycott.com/~phil/antispam/rbl-bad/rbl-bad.html
pgp00000.pgp
Description: PGP signature
