Shouldn't GNU tar be ignoring /proc with --one-file-system?

[Kirk Strauser]

I use Amanda to make nightly backups of a bunch of servers using GNU tar. However, gtar doesn't seem to respect its --one-file-system flag with /proc. Amanda runs a variation of this command:

    # /usr/local/bin/gtar --create --file - --directory / --one-file-system --sparse --ignore-failed-read --totals . > /dev/null
    /usr/local/bin/gtar: ./proc: file changed as we read it

Before I file a bug report, can anyone think of a legitimate reason why gtar would be touching /proc at all?

Kirk