Folks,
Thanks a *lot* to those who suggested I try fsck -cc - that took six
hours, and at the end, I was standing there, and it tells me that
there's two back blocks, one was /dead/base.pp, and... (wait for it)
bad blocks, in node 1.
I said yes, fix them, and rebooted, and I don't see complaints.
mark "and there was much rejoicing"