"tetex" is used to add tetex support to a package. In the case of gnucash, tetex is only required to build documentation, so is covered by the "doc" use flag instead. Same applies to "graphviz" USE flag. The existing behaviour (USE=doc emerges no documentation unless other flags are set) is obviously odd.
I just made a change to 2.0.2, please check and approve
Both "doc" and "tetex" are still in IUSE. There is no need for a tetex USE flag when latex is only required to build documentation, since this is already covered by the "doc" USE flag.
2.0.2 is fixed (and 2.0.3 will have it). We'll get 2.0.2 into the stable track early in the new year
