This seems to have worked the best of all, after I turned off buffering for STDOUT/STDERR, with code such as this:

my ($ofh) = select(STDOUT); $| = 1; select($ofh);
$ofh = select(STDERR); $| = 1; select($ofh);

my ($out, $err);

run (
    [ '/usr/sbin/pkgrm', 'VRTSvxvm' ],
    '>', sub { $out .= $_[0]; print $_[0] },
    '2>', sub { $err .= $_[0]; print $_[0] },
    );
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Now, if the program I was running demands that it connects to a pty before it will unbuffer STDOUT/STDERR properly, what could I do? I've tried the following, but it doesn't send any output to the screen:

use IPC::Run qw(run);

my ($out, $err);

run (
    [ '/usr/sbin/pkgrm', 'VRTSvxvm' ],
    '>', sub { $out .= $_[0]; print $_[0] },
    '>', '>pty>',
    '2>', sub { $err .= $_[0]; print $_[0] },
    '2>', '>pty>'
    );

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