Guillem Jover writes ("dpkg 1.13.24 hint and next upload"):
> The first patch is the one from Brendan O'Dea, that I reverted prior
> to uploading .23.
>
> * Require POSIX inside subprocerr in controllib.pl. Closes: #390636
As I say, I think the right answer is
use POSIX;
at the top. Originally the only reason I didn't do this was because
POSIX.pm wasn't necessarily available - indeed, we may have been using
Perl 4 at the time.
Ian.