Классический пример:
./configure --prefix=/usr/local/testdir

Как повторить данную конструкцию при использовании нового менеджера пакетов PKG[NG]?
Переменную PREFIX=... оно игнорирует:

ASSUME_ALWAYS_YES=YES PREFIX=/usr/local/testdir pkg install openssl ..

Updating FreeBSD repository catalogue...
FreeBSD repository is up-to-date.
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Checking integrity... done (0 conflicting)
The following 1 packages will be affected (of 0 checked):

New packages to be INSTALLED:
    openssl: 1.0.1_18

The process will require 8 MB more space.
[1/1] Installing openssl-1.0.1_18...
[1/1] Extracting openssl-1.0.1_18... done
Message for openssl-1.0.1_18:
Copy /usr/local/openssl/openssl.cnf.sample to /usr/local/openssl/openssl.cnf
and edit it to fit your needs.