catkin build with install fails after changes in a header file

edit

I have a ROS melodic workspace where I'm compiling with catkin tools.

Catkin is initialize to build in a separate directory and to create an install space:

catkin config -s /root/src/my_ws/src --install --cmake-args "-DCMAKE_BUILD_TYPE=Debug"

I then build the entire workspace with

catkin build

which works fine.

I have a problem when I make a change in a header file that is also installed.

E.g. I have a catkin package with the following structure

.
├── CMakeLists.txt
├── include
│   └── my_lib
│       ├── MyLib.hpp
├── package.xml
├── README.md
├── src
│   └── MyLib.cpp

In that CMakeLists.txt I have

install(
  DIRECTORY include/${PROJECT_NAME}/
  DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
  FILES_MATCHING PATTERN "*.hpp"
)

If I now make a change in MyLib.hpp and MyLib.cpp , catkin build will fail until I do a catkin clean. The reason appears to be that the MyLib.hpp file in the install/ space is used to compile MyLib.cpp, i.e. the order of operations is wrong.

Is there something I need to do differently in my CMakeLists.txt or is this a bug?