WARNING: This snapshot is not an Opera Next build. It will default to upgrading your stable Opera.
If you would prefer to install this build alongside your stable Opera installation, use one of the tar.xz packages and follow one of these guides:
Installing a second copy of Opera under Gnome and Unity
Installing a second copy of Opera under KDE
Installing a second copy of Opera under Xfce
Alternatively here is a quick, generic guide:
./install --user --unattended --name opera-12.1
Notes: A second copy of Opera is now installed alongside the stable version. You can confirm this by looking for an "Opera 12.1" entry in your Applications menu. If it doesn't display immediately, log out and back into your desktop environment.