Corrupted ports.tar file?

[Dave Horsfall]

Early MacBook Pro, High Sierra 10.13.6, MacPorts 2.7.2.

When doing my weekly MacPorts maintenance (doesn't everyone?), I saw this 
during a "port reclaim" (automatically requested):

    Found no inactive ports.
    --->  Building list of distfiles still in use
    Warning: It looks like your PortIndex file for rsync://rsync.macports.org/macports/release/tarballs/ports.tar may be corrupt.
    Warning: Port bzip2 not found: 
    Warning: It looks like your PortIndex file for rsync://rsync.macports.org/macports/release/tarballs/ports.tar may be corrupt.
    Warning: Port db48 not found: 
    Warning: It looks like your PortIndex file for rsync://rsync.macports.org/macports/release/tarballs/ports.tar may be corrupt.

Etc; I do have "bzip2" and so on.

Haven't seen that before; what's going on?  A following "port upgrade 
outdated" saw no problems...

-- Dave