Apparently, though unproven, at 23:21 on Saturday 14 May 2011, William Hubbs did opine thusly:
> On Sat, May 14, 2011 at 11:36:29AM -0400, Willie Wong wrote: > > There's no big harm, except that you may end up rebuilding a bunch of > > packages. One way to get a lot of hands-on control on precisely what > > USE you want it via the "-*" flag. But be VERY careful if you are > > going to use it. A USE variable set in /etc/make.conf starting with it > > > > USE="-* X vim ..." > > > > will use nothing but those variables (plus the package specific ones > > specified in /etc/portage). There are certain flags that you most > > likely don't want to turn off: cxx, posix, and threads for example. > > > > It is a powerful tool; which means you can also seriously hurt > > yourself from it. > > PLEASE PLEASE PLEASE DO NOT DO THIS. > > It turns off all use flags set in profiles as well as use flag defaults > set in ebuilds. > > The safer way, and the way I would recommend, is to use something like > euse from gentoolkit to figure out which flags are on and turn off the > ones you do not want in make.conf instead of turning off everything and > trying to turn back on the ones you do want. Agreed. "emerge --info | grep USE" reveals what an enormous task it is to fix USE=-*. Not only an enormous task but a fruitless one too - most of the flags will just get re-enabled! Most people advocating this on list threads and forums, want a minimal system without all the KDE/Gnome/etc bloat. The correct way to do that is to use a minimal profile then examine the now much smaller emerge --info and disabled the few remiaining USE flags one does not want. -- alan dot mckinnon at gmail dot com