attachment follows
Created attachment 86754 [details, diff] mythtv-0.19_p9163-r1.ebuild.diff - check for correct Qt version - die only once, instead letting users suffer from a try again cycle I modified it quick and dirty without checking for typos or if it compiles.
Thx. I've been actually wondering and asking in #gentoo-dev if something very similar with this is valid because I've wanted to do it. Now I know it is valid. I commited your patch with some cleanups.