Looks like a typo. - !!dev-libs/gnome-build + !dev-libs/gnome-build
What do you mean with "depends on gnome-build"? Does emerge want to install it (give emerge's out in this case)? !! is not a typo. With EAPI 2 two kinds of blocks have been introduced.
Sorry, I wasn't more explicit because I thought it was a trivial bug. Thanks for the correction. The first time I tried to emerge anjuta-2.26.2.0, gnome-build was not uninstalled and I got this error: This package will overwrite one or more files that may belong to other packages (see list below). You can use a command such as `portageq owners / <filename>` to identify the installed package that owns a file. If portageq reports that only one package owns a file then do NOT file a bug report. A bug report is only useful if it identifies at least two or more packages that are known to install the same file(s). If a collision occurs and you can not explain where the file came from then you should simply ignore the collision since there is not enough information to determine if a real problem exists. Please do NOT file a bug report at http://bugs.gentoo.org unless you report exactly which two packages install the same file(s). Once again, please do NOT file a bug report unless you have completely understood the above message. Detected file collision(s): /usr/bin/gbf-am-parse /usr/bin/gbf-mkfile-parse Therefore I uninstalled gnome-build and tried to build anjuta again, but gnome-build kept being pulled. After removing a ! from the ebuild, I could successfully emerge anjuta and I filed this bug. After reading your request, I deleted the ebuild in my overlay and tried the official (the difference being only a !) expecting gnome-build to be pulled again, but only anjuta did, which is the normal behaviour. I did some more tries, with gnome-build installed or not before anjuta, with ! or !!, but I couldn't reproduce the bug. Anyway, !! surely is the correct choice, so I'm marking this bug as worksforme unless I can reproduce it again.