Any ideas ?
Well if you really compiled it before on the command line and the target is up-to-date therefore, C::B is telling you the truth: Nothing to be done.
Try to re-build your project if you really want to do a build from scratch.
For an explanation: C::B tries to minimise the build effort by checking the file's date stamps before compilation. If an application is newer than
all source files that belong to this application the build is omitted. This is by design and very helpful for large scale projects. To overcome this feature, you have to use
re-build which forces C::B to ignore the date stamps of the files.