gspiceui INSTALL files says: The recommended version of the wxWidgets library is v2.8.x however v2.6.x may still be used. (Note : wxWidgets v2.6.x may generate some console spew on standard error which may be ignored eg. "gspiceui 2>/dev/null".) [...] If no package still needs compat-wxGTK26 we could get rid of it.
I'm working on it