I tried gnak, it works indeed!

I didn't know of Guigui. I'm happy it exists and that the web is slowly losing, but I don't understand why all these newish GUI frameworks never bother to implement support for the Linux primary clipboard.

I guess all immediate-mode frameworks end up being very ugly for some reason. There was another one in Go that I tried a while ago and it was sad, but I guess for "tools" like nak they're fine.