original.pl

use strict;
use Devel::Cover;

my $pid = fork();
if ( $pid ) {
    wait;
} else {
    system "/bin/ls"; # shows output of ls on my console
    # exec "/bin/ls"; # doesn't show output of ls :/
}

with_report.pl

use strict;
use Devel::Cover;

my $pid = fork();
if ( $pid ) {
    wait;
} else {
    Devel::Cover::report(); # dies
    exec "/bin/ls";
}

with_report_and_eval.pl

use strict;
use Devel::Cover;

my $pid = fork();
if ( $pid ) {
    wait;
} else {
    # WORKS!!!!
    eval { Devel::Cover::report() };
    exec "/bin/ls";
}