OSNews

First, remember that "xmms" enables xmms support, while "-xmms" directly disables xmms support when compiling. That being said, it is possible to compile all kinds of spiffy KDE and GNOME things while using fluxbox (as I do) in Gentoo. Also, you have to pay attention to the flags that you use, because sometimes all this customization can give you some bizarre results. My first example is when I emerged SAMBA and had "ldap" in my USE line (as I intended on using an LDAP server at some point), and when I wanted to start adding SAMBA accounts, it complained that it wasn't configured with an LDAP server and couldn't process my request. So, I did a little search on the forum, and found out about my ldap flag. I then switched it from "ldap" to "-ldap", and re-emerged SAMBA. Afterward, it worked fine as it compiled with the new flag arrangement and didn't compile any LDAP support into the app. Another example is when I was using fluxbox for a while, and decided to try out KDE for a bit. I had the Qt libraries and and kde-base since I was using some KDE apps and utils in fluxbox (such as K3B and Konqueror) so I decided to run the desktop itself. Well, when I went into it I didn't have any working sound, while I did have sound working just fine in fluxbox using ALSA with my Audigy. So, I checked out my flags and found that I had "-arts" in it, which disabled support for the KDE sound server. Later that night, before I went to bed I re-emerged kde-base and used "arts" rather than "-arts", and when it was done sound worked in KDE.

Now, why bother with "-this" or "-that" when not listing it is the same thing? Well, it isn't it the same thing, that's why :-). The make.global file contains a few flags (or it can contain whatever you want, but I wouldn't recommend altering it) of its own. If you add flags to make.conf, these are then *added* to whatever make.global has. However, if you decided to not have, say, "gnome" support in an application and didn't enter "-gnome" in your make.conf USE line then it might *still* be compiled into your application if make.global had it in there. This is a *major* reason why you should *not* alter make.global, as it is meant to control your system reference point, and changes to make.conf can override it if you want. Now, if for some weird reason you had the "gnome" flag in make.global, and you put "-gnome" in your make.conf file, you will *not* have gnome support compiled into your app as make.conf will override make.global. Cool eh? Now, what's even better, is that you can do a one-time flag setting in your emerge command with something like "USE = -wavelan emerge pcmcia-cs", and this will emerge (compile and install) the current stable pcmcia-cs package without wavelan support *even if* you have a "wavelan" flag in your make.conf. I have used this in certain pcmcia-cs packages to enable monitor mode on my Orinoco NICs for my laptops so I can use Kismet and AirSnort.

HTH