How to fix undefined reference to ... in c++

Question

I am trying to compile mathgl with fltk on a linux debian. In the mathgl directory, I do the followin cmd to configure the compilation :

cmake -Wno-dev -D enable-hdf5=on -D enable-jpeg=on -D enable-png=on -D enable-fltk=on -D enable-qt4=on

and the result is:

...................................

 `[82%] Linking CXX executable mglview

   cd    /home/sosroot/MathLib/mathgl/utils && /usr/local/bin/cmake -E    cmake_link_script CMakeFiles/mglview.dir/link.txt --verbose=1
   /usr/bin/c++   -fopenmp -O3 -DNDEBUG  -rdynamic    CMakeFiles/mglview.dir/mglview.cpp.o  -o mglview    -Wl,-rpath,/home/sosroot/MathLib/mathgl/widgets:/home/sosroot/MathLib/mathgl/src:/usr/local/HDF_Group/HDF5/1.10.5/lib: ../widgets/libmgl-fltk.so.7.5.0 /usr/local/lib/libfltk_images.a    /usr/local/lib/libfltk_forms.a /usr/local/lib/libfltk_gl.a -lGL    /usr/local/lib/libfltk.a -lSM -lICE -lX11 -lXext -lm    ../src/libmgl.so.7.5.0 -lGL -lGLU -lpng -lz -ljpeg    /usr/local/HDF_Group/HDF5/1.10.5/lib/libhdf5.so.103.1.0 -ldl -pthread    -lm  

../widgets/libmgl-fltk.so.7.5.0: undefined reference to `XftFontOpenXlfd' 
../widgets/libmgl-fltk.so.7.5.0: undefined reference to `XftListFonts'  
......................................................................

../widgets/libmgl-fltk.so.7.5.0: undefined reference to `XRenderComposite'

../widgets/libmgl-fltk.so.7.5.0: undefined reference to `XRenderQueryExtension'

../widgets/libmgl-fltk.so.7.5.0: undefined reference to `XRenderCreatePicture'

collect2: error: ld    returned 1 exit status

utils/CMakeFiles/mglview.dir/build.make:104: recipe for target 'utils/mglview' failed

make[2]: *** [utils/mglview]    Error 1

make[2]: Leaving directory '/home/sosroot/MathLib/mathgl'

CMakeFiles/Makefile2:1041: recipe for target    'utils/CMakeFiles/mglview.dir/all' failed

make[1]: ***    [utils/CMakeFiles/mglview.dir/all] Error 2

make[1]: Leaving directory    '/home/sosroot/MathLib/mathgl'

Makefile:132: recipe for target 'all'    failed

make: *** [all] Error 2`

can some one help me ?

Thank you.

Possible duplicate of [What is an undefined reference/unresolved external symbol error and how do I fix it?](https://stackoverflow.com/questions/12573816/what-is-an-undefined-reference-unresolved-external-symbol-error-and-how-do-i-fix) — 1201ProgramAlarm, Mar 31 '19 at 21:54

score 0 · Answer 1 · answered Mar 31 '19 at 21:25

Looks like you are missing the xwindows libraries. Try adding the following libraries to the link line

-lX11 -lXi -lXinerama -lXft -lXext -lsupc++ -lfontconfig -lXrender

You may also need to add the -L to tell the linker where to find the libraries.

How to fix undefined reference to ... in c++

1 Answers1