Building xfce-extra/xfce4-notes-plugin/xfce4-notes-plugin-1.11.2 fails with checking for gtksourceview-4 >= 4.0.0... not found *** The required package gtksourceview-4 was not found on your system. *** Please install gtksourceview-4 (atleast version 4.0.0) or adjust *** the PKG_CONFIG_PATH environment variable if you *** installed the package in a nonstandard prefix so that *** pkg-config is able to find it. Providing x11-libs/gtksourceview makes all well with the world. Providing gui-libs/gtksourceview-5.14.2 does not allow xfce4-notes-plugin to find it. They are two different major versions.