The new scribus 1.3.4 ebuild didn't have the cairo use flag to enable compilation with cairo. There are some nice features associated with this.
Created attachment 122843 [details]
ebuild with a cairo use flag
This ebuild adds the use flag.
cairo is the default for Scribus. in 1.3.5, we really only support cairo
All I know is that the original ebuild didn't not activate Cairo on my computer. Scribus 1.3.4 ended up without some of the transparency blending effects that I wanted, and they depend on Cairo. When I re-emerged it with the modified ebuild and the cairo use flag, it built with support and those features were enabled.
I've now added a 1.3.4-r1-ebuild which hard-enables cairo. While cairo isn't really a dep for 1.3.4, the devs strongly suggest using cairo-support and it will be required for 1.3.5.