JFYI...
After a long time, I have launched my Ubuntu VM and I upgraded it from v24 to v26.
I tried whether C::B still works and noticed in its About dialog, that wxWidgets is reported as 3.2.4 in the build info line but 3.2.9 in the Information tab. Using Ctrl+Alt+MiddleClick confirms that wxWidgets is indeed 3.2.9.
Unfortunately, I have no idea where I got C::B from and how to check whether the reported GCC version is correct.
When the same version nightly is run on Windows, both wxWidgets versions are the same there.