Sure, Adobe hasn’t updated the thing in like a year, but I’m sick enough of spyware infestations to have already eradicated the Windows scourge from all my machines, and can’t afford to buy yet another computer right now, Mac or otherwise. So it’s worth my while to try the “alpha” Linux version of Flex Builder. Even though I already paid full price for a not-so-alpha Flex Builder license. Maybe I’m crazy. Yeah, probably.
First off, install a 3.3 version of Eclipse directly from a .tar file in your home directory. Flex Builder Linux Alpha works only with 3.3, will not work with 3.4 (some assertion will fail when you open an editor). Go to the “old versions” link on eclipse.org to download it.
Furthermore, the Flex Builder Linux Alpha installer needs to be able to write to Eclipse’s directory, but for some reason if you install Eclipse somewhere like /opt where you need to be root to do it, and then try to run the Flex Builder Linux Alpha installer as root to install it there, that also doesn’t work. What will happen is you’ll start up Eclipse and it will appear as though you’d never tried to install Flex Builder at all. I have no idea why this is.
So it kind of sucks a little that you can’t do it in a “site-wide” install, and this would probably not be a problem if Adobe would just package the thing up as a normal Eclipse plugin instead of an installation executable with .bin at the end of the filename. I don’t get that. Adobe obviously still doesn’t quite understand the kind of modularity philosophy that pervades Linux-land.
So untar Eclipse 3.3 in your home directory, then run the installer as yourself rather than as root, the default install directory for Flex Builder will do fine, point it to the directory where Eclipse is at, and that’s pretty much that.
Point is, don’t try to get all fancy about it, or try to install it over however your distro’s package system installs Eclipse, or insist on the latest Eclipse. What I’ve just described seems to be the only way that actually works.