Unable to install smartmontools v6.5-1 into an updated Mac OS X v10.5.8/Leopard...

Hello.

I just downloaded 
https://sourceforge.net/projects/smartmontools/files/smartmontools/6.5/smartmontools-6.5-1.dmg/download 
into a very old (early 2008) 15" MacBook Pro with its new updated Mac OS 
X v10.5.8/Leopard on an external USB HDD since I am trying to see if its 
internal HDD is going bad (not booting up Mac OS X fully even in safe 
mode and others). I am still able to access this internal HDD from the 
external HDD's OS X v10.5.8 though.

Opening its downloaded smartmontools-6.5-1.dmg and running its 
smartmontools-6.5-1.pkg shows "Operating could not be completed. 
(com.apple.installer.pagecontroller error -1.) Couldn't open 
'smartmontools-6.5-1.pkg'" error -- 
http://image.prntscr.com/image/fe7ddd7471f0472d918b0a881d060634.png fr a 
screen shot/capture.

Thank you in advance. :)
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