libstdc++.so.6: version `GLIBCXX_3.4.21' not found error
Well, I asked this question myself. I just downloaded the snapshot from Apple's official website. The thing was that I was following a tutorial which tied to download the snapshot for ubuntu via wget, but I got the snapshot for ubuntu 15 instead of the one for ubuntu 14. My guess is that ubuntu 15 is newer and therefore it has a newer version of the thing I asked....