With a new machine and a new installation of Debian, I decided to switch from wx 2.8.12 to wx 2.9. I was able to install Code Blocks but I am unable to compile: no wx header is found.
(1) wx-config exists and can be run from the commandline. wx-config --cflags produces, among others, -I/usr/include/wx-2.9
(2) the directory exists, it contains the wx folder and, subsequently, all needed headers. The headers can be read.
(3) The Compiler Options of the project do contain `wx-config --cflags`
(4) When compiling, the build log shows -I/usr/include/wx-2.9 on the commandline of the compiler.
(5) Once I start compiling my project, I get "wxColour does not name a type". Similarly, wxSize does not name a type

(6) Adding /usr/include/wx-2.9 explicitly to the Search Options does not help.
I seem I forget to set something somewhere. Yes, the project is now created as wx 2.9 project, not a wx 2.8.12 project, and it is an "old" project which compiles under 2.8.12 without errors and warnings. What is wrong?