The switch to GNU `install-info' from the dpkg version means that we
generate a (largely bogus) `dir.gz' file. This gets picked up by
`update-info-dir' and we lose the original `dir'. This in turn is a
hopeless bummer because Emacs doesn't look for a `dir.gz' file, only an
uncompressed `dir', and can't find any Info documents as a result.
So terminate the offending file with extreme prejudice in the nick of
time.