I'm using Mac OS X 10.7.5, and I'd like to know this. I started the download for OS X Yosemite yesterday on User A, accidentally – I was going to start it on User B (me). Now, I didn't notice this until I switched to User B and let the computer sleep so that it could download the update while still staying alive (I plugged it in, too).
Now, when I woke up this morning, and switched back to User A, I got a couple of funny things happening.
First of all, it said Could not download OS X Mountain Lion due to an unknown error; the application can be found in Purchases in the App Store
in a dialog window. Not cool, but I wasn't even downloading OS X Mountain Lion!
Next, when I clicked F4
on my Macbook Pro to see my Launchpad, OS X MAVERICKS was in there and paused.
Finally, Yosemite seemed to be still downloading; there was a Yosemite button icon thing, and it said downloading.
This brings me to my question: Yosemite didn't seem to have downloaded at all. It was still at the first progress bar image (or so it seemed). So, is it supposed to not download when I'm not in the same user as the one which started the download?
I'd really like to know this, because my internet downloads at 300 KBpS on average, and it's really slow, so I'd like to not be wasting time on getting the download to work when it's not going to work at all.
Best Answer
The App Store saves its files to a temporary folder until it is completely downloaded. This temporary download location is different for each user of the Mac. So, it's possible (likely) that you could have two partially downloaded copies of the same application. For Yosemite, and its multi-gb package size, this is not trivial.
You can see if the file is currently downloading in a number of ways. 2 & 3 require some familiarity with Terminal.app.
sudo lsof | grep storeage
getconf DARWIN_USER_CACHE_DIR
for the currently logged-in user.