The new Release 20.03 is out! You can download binaries for Windows and many major Linux distros here .
C:\wxWidgets-3.2.1\lib\gcc_dll\mswuC:\wxWidgets-3.2.1\lib\gcc_dll\mswud
Actually, all the lib files in that directory are 32s. There is no libwxmsw32u.a or libwxmsw32ud.a but plenty of others for ribbon, aui, xrc, webview, html, core ...etc. So should I download the non-debug version?