CMake compiles executable before generating message libraries

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Hello,

I face the problem that I get an compiling error while compiling something that is for example using a custom service. The error is that it can't find the headerfile or library that should be generated during catkin_make. If I compile it with one core (catkin_make -j1) it works fine. If it is compiled once the error does not occur again cause the library exists - till the next clean

I guess I defined something wrong in the CMakeList or is it a general problem?

Thanks in advance

Chris