Install "unsupported" Hewlett Packard printer on OSX Yosemite

I believe everyone has it's own "favorite" (but old) model of printer that meets one need, is featured as you like, but the manufacturer tends to "forget" it, at least on the software support side of it. That happened to me with Hewlett Packard M1522n MFP printer, that knows everything I need (laser printer, duplex, flatbed and feeder document scanning). Still, since OSX Lion, scan support was removed as "supported feature" from Apple provided HP drivers. That's fine, as HP "native" scanner software was working just fine on all recent OSXes (10.7, 10.8 and 10.9).

Still, on Yosemite the HP driver installer presents you a strange message "Unsupported operating system, supported versions are 10.6 and above"! Must be joking.

By the way, this reminds me of windows 9 thingie.

Luckily, there is a way to install the software: thanks to Justin's blog, one can easily force installer in belief it's about to install on 10.9 (that's what I did), which is "above" 10.6 (while 10.10.1 is seemingly not).

Word of caution: OSX knows to go hayway during this operation (Finder did it for me). So, do not reboot with changed plist, and quit any application running! What I did was prepare to launch installer (mounted the dmg), made a copy of the plist file, edited the plist by setting version to "10.9", performed the install, and immediately mv the "original" back into place (to reset the version to actual one). During install installer restarted Finder, and it went nuts (some icons did disappear). Then I verified that HP Scan still works, and did a reboot (as the plist file change did trigger some strange things).

HP Scan app still works and handles the scanner just fine on Yosemite.