Odd problem while installing XCode 6 beta 3

I installed XCode 6 beta 3 a few times on several Mavericks OS and had no problem.  But today do the exact same thing on a clean Mavericks OS installation (on the first OS partition on my MacMini late 2009 model), I got error while "components" were being installed.  And then after I tried a few times, the problem went away.  That is so ... odd ...

And then the machine eventually frozen up.  And I thought, damn beta software.  So I tried to bootup to a clean clean Mavericks OS installation (first disk partition).  In fact, I went so far by yanked out all the USB connection, so now everything is running on the MacMini itself.  Eventually, after waiting for a long while, the system bootup, but then it get hanged, and stuck there with the spinning beach ball.

With that I am pretty giving up on this machine.  It's pretty much unusable unless I spent time to open up the machine, either try testing the memories by swapping memory sticks, or swap out the harddisk, which I tend to think that is the real problem.  But basically the Macmini is dead to me, not even reliable enough to be used as a download machine.  As of now, the screen was loaded, and then just hung again.  RIP MacMini.
But
I found the OSX Mavericks VM provides me much better the usage and development experience.  But OSX Yosemite 10.10 Preview 3 was pretty slow.  So for now I'll probably just stick with OSX Mavericks VM .