/tmp>perl -T taint.pl /dev/null
Insecure dependency in open while running with -T switch at /usr/lib64/perl5/IO/File.pm line 184.

/tmp>perl -MCarp::Always -T taint.pl /dev/null
Insecure dependency in open while running with -T switch at /usr/lib64/perl5/IO/File.pm line 184.
        IO::File::open(IO::File=GLOB(0x1520be8), "/dev/null", "w") called at taint.pl line 10

/tmp>