F2 or menu "View" -> "Logs".
This will not help, because the Log is visible.
But from now I can only see error messages and no more build messages in the build log window
The behaviour with custom makefiles has changed.
It behaves (more or less) similar to C::B own project-files:
change "Settings -> Compiler and debugger... -> Global compiler settings -> [the compiler you use] -> Other settings(rightmost tab)" "Compiler logging" to "Full commandline".