This bug is old, but i have the problem too. $IPC::Run::VERSION == '0.89'
OS: debian squeeze. I installed IPC::Run with cpan. running something like this: my @command = ("sfdisk", ...); my $command_out = ''; my $command_in; my $command_h = start \@command, '<pty<', \$command_in, '>pty>', \$command_out; while(pump $command_h) { ... # Do some stuff with sfdisk ... } finish($command_h); When using my default locale (fr_FR.UTF8), i get this error: 'ack Erreur d'entrée/sortie: read( 4 ) at /usr/share/perl5/IPC/Run/IO.pm line 558' When setting LC_ALL=POSIX, everything goes well.