$ sudo make -C pyformex/extra build make: Entering directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra' make -C gts build make[1]: Entering directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/gts' gcc inside.c `pkg-config --cflags --libs glib-2.0 gts` -DNDEBUG -o gtsinside gcc smooth.c `pkg-config --cflags --libs glib-2.0 gts` -DNDEBUG -o gtssmooth gcc coarsen.c `pkg-config --cflags --libs glib-2.0 gts` -DNDEBUG -o gtscoarsen gcc refine.c `pkg-config --cflags --libs glib-2.0 gts` -DNDEBUG -o gtsrefine gcc set.c `pkg-config --cflags --libs glib-2.0 gts` -DNDEBUG -o gtsset make[1]: Leaving directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/gts' make -C postabq build make[1]: Entering directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/postabq' gcc -Wall -o postabq postabq.c make[1]: Leaving directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/postabq' make -C dxfparser build make[1]: Entering directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/dxfparser' g++ `pkg-config --cflags --libs dxflib` dxfparser.cc -o dxfparser /usr/bin/ld: /tmp/cc3OxBkv.o: in function `main': dxfparser.cc:(.text+0x219): undefined reference to `DL_Dxf::DL_Dxf()' /usr/bin/ld: dxfparser.cc:(.text+0x3c7): undefined reference to `DL_Dxf::in(std::__cxx11::basic_string, std::allocator > const&, DL_CreationInterface*)' /usr/bin/ld: dxfparser.cc:(.text+0x421): undefined reference to `DL_Dxf::~DL_Dxf()' /usr/bin/ld: dxfparser.cc:(.text+0x489): undefined reference to `DL_Dxf::~DL_Dxf()' collect2: error: ld returned 1 exit status make[1]: *** [Makefile:78: dxfparser] Error 1 make[1]: Leaving directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra/dxfparser' make: *** [Makefile:15: build-dxfparser] Error 2 make: Leaving directory '/mnt/c/Users/Holzschuh/Downloads/pyformex-2.4/pyformex/extra'