I've had this problem the last couple of times that a new build of the
wxWidgets package was released. You will have to checkout a copy of the
mingw package repo on github and rebuild the wxPython package with the
latest compiler (gcc 10) to fix the ABI warning. It's not terribly
difficult just do the following:
* Launch the msys2 console. This does not work with a mingw console.
* Run `cd /to/your/src/folder`
* Run `git clonehttps://github.com/msys2/MINGW-packages.git`
* Run `cd ./MINGW-packages/mingw-w64-wxPython`
* Run `makepkg-mingw`
* Wait a really long time for both 64 and 32 bit packages to build.
* Run `pacman -U mingw-w64-x86_64-wxPython-3.0.2.0-9-any.pkg.tar.xz` or
`pacman -U mingw-w64-i686-wxPython-3.0.2.0-9-any.pkg.tar.xz` depending
if you are using mingw64 or mingw32.
* Reconfigure your KiCad build. You may have to do a clean configure.