xorg-proto-2018.4 has "inherit meson" line in ebuild It seems that xorg-proto-2018.4 build with no meson just fine. Why xorg-proto-2018.4 inherits meson ?
Because meson is the build system used by xorg-proto. It is needed to be able to build. I don't know how you managed to build it without the inherit, probably didn't test what you changed on accident or something.
I was told it's likely you adjusted it to use autotools instead. That will soon be removed upstream and meson is the suggested way. We are not going to move back to the deprecated build system just to avoid a build system that's superior to autotools, has less dependencies, and is the future only build system for many projects.
I did modify ebuild by removing "inherit meson" string only. And it builds with no problem on genuine fully updated gentoo system with no meson installed. Mart Raudsepp, you as maintainer eliminate the choice and force people to use stuff you personally like. This is ugly way of systemd adepts.
First, Mart is _not_ the maintainer of xorg-proto package. Second, we provide choice where it makes sense. It makes absolutely _no_ sense to provide different ways of how to build this package. Upstream decided to move the build system to meson so we are simply following their decision. Just because upstream didn't remove the old autotools build system yet doesn't mean we are supposed to still use it.
