Tutorial Step 9 error

Hello again.

In setting up to build for step 9 of the online tutorial, I Get a different error than theone the tutorial says I should expect.

I followed all the sintructions given up to the point wehre it says what should happen if I build (before changing the library t a static with PIC). I see this error - not sure what I missed:

14:58 [mrichter@mrichter-linux:~/Downloads/cmake-Help-guide/tutorial/Step09] $ cmake .
– The C compiler identification is GNU 8.3.0
– The CXX compiler identification is GNU 8.3.0
– Check for working C compiler: /usr/bin/cc
– Check for working C compiler: /usr/bin/cc – works
– Detecting C compiler ABI info
– Detecting C compiler ABI info - done
– Detecting C compile features
– Detecting C compile features - done
– Check for working CXX compiler: /usr/bin/c++
– Check for working CXX compiler: /usr/bin/c++ – works
– Detecting CXX compiler ABI info
– Detecting CXX compiler ABI info - done
– Detecting CXX compile features
– Detecting CXX compile features - done
– Configuring done
– Generating done
– Build files have been written to: /home/mrichter/Downloads/cmake-Help-guide/tutorial/Step09
14:58 [mrichter@mrichter-linux:~/Downloads/cmake-Help-guide/tutorial/Step09] $ cmake --build .
Scanning dependencies of target Tutorial
[ 11%] Building CXX object CMakeFiles/Tutorial.dir/tutorial.cxx.o
/home/mrichter/Downloads/cmake-Help-guide/tutorial/Step09/tutorial.cxx:7:10: fatal error: MathFunctions.h: No such file or directory
#include “MathFunctions.h”
^~~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [CMakeFiles/Tutorial.dir/build.make:63: CMakeFiles/Tutorial.dir/tutorial.cxx.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:371: CMakeFiles/Tutorial.dir/all] Error 2
make: *** [Makefile:163: all] Error 2
14:58 [mrichter@mrichter-linux:~/Downloads/cmake-Help-guide/tutorial/Step09] $

Help?

Do you have

target_link_libraries(Tutorial PUBLIC MathFunctions)

in the top-level CMakeLists.txt file and

target_include_directories(MathFunctions
                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
                           )

in MathFunctions/CMakeLists.txt?

The top level change was missing.

Thanks.