Nope not intended. I didn't know it was something that was needed. I'll add it.
Apparently this is a neovim decision. They decided to never set gui_running to 1. https://github.com/neovim/neovim/pull/4155
I have confirmed the same in neovim-qt
Ah, dang, I should have checked. neovide is actually the first GUI project that made me come out of my "shell"…
A quick googling revealed that the solarized colorscheme apparently received an updated fork in the meantime, so I'll just use that instead.
Thanks!
Badump tsss!