'pkg upgrade' produces 'conflict found' warnings

[Yuri]

Proceed with upgrading packages [y/N]: y
Checking integrity...
Conflict found on path /usr/local/bin/a2p between 
perl-5.16.3_1(lang/perl5.16) and perl-5.14.4_2(lang/perl5.14)
Conflict found on path /usr/local/bin/c2ph between 
perl-5.16.3_1(lang/perl5.16) and perl-5.14.4_2(lang/perl5.14)
Conflict found on path /usr/local/bin/config_data between 
perl-5.16.3_1(lang/perl5.16) and perl-5.14.4_2(lang/perl5.14)
Conflict found on path /usr/local/bin/corelist between 
perl-5.16.3_1(lang/perl5.16) and perl-5.14.4_2(lang/perl5.14)
...
Binary upgrade fails this way.

This system is 9.2-STABLE with PKGNG in use, and perl has been upgraded 
to perl5-5.16.3_1. So I assume conflicts come from the remote packages?
This command has been run, if this matters: pkg set -o 
lang/perl5.14:lang/perl5.16

This message should be clarified: where the conflict is found exactly? 
The current message isn't user friendly. User didn't do anything wrong, 
and the message doesn't add clarity as to what the problem is.

Yuri