Linux building problem

[humayunbd]

dell@dell-Vostro-14-3468:~/Downloads/mqa$ cmake ../MQA_identifier-1.3/gui/
-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- 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/dell/Downloads/mqa

dell@dell-Vostro-14-3468:~/Downloads/mqa$ make
Scanning dependencies of target MQA_identifier_gui_autogen
[ 20%] Automatic MOC and UIC for target MQA_identifier_gui
[ 20%] Built target MQA_identifier_gui_autogen
Scanning dependencies of target MQA_identifier_gui
[ 40%] Building CXX object CMakeFiles/MQA_identifier_gui.dir/MQA_identifier_gui_autogen/mocs_compilation.cpp.o
cc1plus: error: /home/dell/Downloads/MQA_identifier-1.3/gui/CMakeLists.txt/../mainwindow.h: Not a directory
make[2]: *** [CMakeFiles/MQA_identifier_gui.dir/build.make:63: CMakeFiles/MQA_identifier_gui.dir/MQA_identifier_gui_autogen/mocs_compilation.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:77: CMakeFiles/MQA_identifier_gui.dir/all] Error 2
make: *** [Makefile:84: all] Error 2
dell@dell-Vostro-14-3468:~/Downloads/mqa$```