我正在尝试在Ubuntu 14.10（Perl v5.20）上安装Proc::Daemon：
$ cpanm Proc::Daemon
--> Working on Proc::Daemon
Fetching http://www.cpan.org/authors/id/A/AK/AKREAL/Proc-Daemon-0.20.tar.gz ... OK
Configuring Proc-Daemon-0.20 ... OK
Building and testing Proc-Daemon-0.20 ... FAIL
! Installing Proc::Daemon failed. See /home/hakon/.cpanm/work/1437385026.3674/build.log for details. Retry with --force to force install it.
完整的日志在这里：http://pastebin.com/8s7ndGaC。 第一次失败的测试似乎是：
# Failed test ''kid.pl' daemon is still running'
# at /home/hakon/.cpanm/work/1437385026.3674/Proc-Daemon-0.20/t/02_testmodule.t line 116.
# Failed test 'stop daemon 'kid.pl''
# at /home/hakon/.cpanm/work/1437385026.3674/Proc-Daemon-0.20/t/02_testmodule.t line 119.
Use of uninitialized value in numeric eq (==) at /home/hakon/.cpanm/work/1437385026.3674/Proc-Daemon-0.20/t/02_testmodule.t line 129.
测试脚本02_testmodule.t位于：https://api.metacpan.org/source/AKREAL/Proc-Daemon-0.20/t/02_testmodule.t（此处为http://pastebin.com/E0n116bA）
测试脚本中的第115-119行：
$pid = $daemon->Status( "$cwd/pid_1.file" );
ok( $pid == $Kid_PID2, "'kid.pl' daemon is still running" );
my $stopped = $daemon->Kill_Daemon();
ok( $stopped == 1, "stop daemon 'kid.pl'" );