FORCE_PKG_REGISTER
 
 問題敘述: 
 當你先前已經用ports 安裝過某一軟體 當你要再次透過ports 安裝同一軟體時,
 很有可能會出現類似下述的錯誤訊息產生.
 
 意思是說 你可以透過 make deinstall 解除安裝 然後透過 make reinstall來再次安裝
 
 若你確定想要*覆蓋*此安裝 可以透過設定 FORCE_PKG_REGISTER 變數達成目標.
 

===> An older version of PORTS資料夾位置 is already installed (軟體版本)
     You may wish to ``make deinstall'' and install this port again
     by ``make reinstall'' to upgrade it properly.
     If you really wish to overwrite the old port of PORTS資料夾位置
     without deleting it first, set the variable "FORCE_PKG_REGISTER"
     in your environment or the "make install" command line.
 
 處理方式:
 只要在make install 時加上 FORCE_PKG_REGISTER="yes" 就可以強制安裝.
 也就是: /usr/ports/資料夾位址/#make install FORCE_PKG_REGISTER="yes"